$AON
Aon plc

2019 Q4 Form 10-K Financial Statement

#000162828020001607 Filed on February 14, 2020

View on sec.gov

Income Statement

Concept 2019 Q4 2018 Q4 2018 Q3
Revenue $2.885B $2.770B $2.349B
YoY Change 4.15% -4.78% 0.38%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin $2.053B $2.003B $1.852B
YoY Change 2.5% -7.65% -4.68%
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization $145.0M $151.0M $40.00M
YoY Change -3.97% 8.63% 0.0%
% of Gross Profit
Operating Expenses $2.191B $2.152B $1.990B
YoY Change 1.81% -6.76% -4.51%
Operating Profit $524.0M $499.0M $262.0M
YoY Change 5.01% -16.97% 2.34%
Interest Expense -$85.00M -$82.00M $69.00M
YoY Change 3.66% 13.89% -1.43%
% of Operating Profit -16.22% -16.43% 26.34%
Other Income/Expense, Net -$3.000M $6.000M $1.000M
YoY Change -150.0% -105.5% -75.0%
Pretax Income $441.0M $421.0M $194.0M
YoY Change 4.75% 3.69% -3.0%
Income Tax $59.00M $49.00M $39.00M
% Of Pretax Income 13.38% 11.64% 20.1%
Net Earnings $382.0M $353.0M $153.0M
YoY Change 8.22% -3041.67% -20.31%
Net Earnings / Revenue 13.24% 12.74% 6.51%
Basic Earnings Per Share $1.59 $1.42 $0.60
Diluted Earnings Per Share $1.58 $1.41 $0.60
COMMON SHARES
Basic Shares Outstanding 234.1M shares 240.8M shares 244.0M shares
Diluted Shares Outstanding 245.6M shares

Balance Sheet

Concept 2019 Q4 2018 Q4 2018 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments $6.082B $4.728B $5.051B
YoY Change 28.64% 267.94% 111.43%
Cash & Equivalents $790.0M $656.0M $484.0M
Short-Term Investments $5.292B $4.072B $4.567B
Other Short-Term Assets $602.0M $618.0M $727.0M
YoY Change -2.59% 113.84% 40.35%
Inventory
Prepaid Expenses $97.00M $97.00M $109.0M
Receivables $3.112B $2.760B $2.656B
Other Receivables $88.00M $113.0M $196.0M
Total Short-Term Assets $16.48B $14.37B $13.35B
YoY Change 14.64% 5.08% -6.44%
LONG-TERM ASSETS
Property, Plant & Equipment $621.0M $588.0M $594.0M
YoY Change 5.61% 4.26% 8.99%
Goodwill $8.165B $8.171B $8.282B
YoY Change -0.07% -2.24% 4.99%
Intangibles $783.0M $1.149B $1.260B
YoY Change -31.85% -33.7% -6.04%
Long-Term Investments $53.00M $54.00M $52.00M
YoY Change -1.85% -5.26% 18.18%
Other Assets $570.0M $448.0M $434.0M
YoY Change 27.23% 45.93% 45.64%
Total Long-Term Assets $12.93B $588.0M $12.25B
YoY Change 2098.81% 4.26% 5.12%
TOTAL ASSETS
Total Short-Term Assets $16.48B $14.37B $13.35B
Total Long-Term Assets $12.93B $588.0M $12.25B
Total Assets $29.41B $26.42B $25.60B
YoY Change 11.29% 1.28% -1.24%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable $1.939B $1.943B $1.600B
YoY Change -0.21% -0.92% 0.76%
Accrued Expenses $186.0M
YoY Change
Deferred Revenue $270.0M $251.0M $266.0M
YoY Change 7.57% -19.29%
Short-Term Debt $0.00 $0.00 $0.00
YoY Change
Long-Term Debt Due $736.0M $251.0M $741.0M
YoY Change 193.23% -16.05% 142.95%
Total Short-Term Liabilities $15.57B $13.30B $12.64B
YoY Change 17.11% 4.24% 1.35%
LONG-TERM LIABILITIES
Long-Term Debt $6.627B $5.993B $5.665B
YoY Change 10.58% 5.75% 0.05%
Other Long-Term Liabilities $877.0M $1.097B $1.090B
YoY Change -20.05% -0.45% 28.84%
Total Long-Term Liabilities $7.504B $7.090B $6.755B
YoY Change 5.84% 4.74% 3.8%
TOTAL LIABILITIES
Total Short-Term Liabilities $15.57B $13.30B $12.64B
Total Long-Term Liabilities $7.504B $7.090B $6.755B
Total Liabilities $25.96B $22.20B $21.27B
YoY Change 16.9% 3.56% 2.89%
SHAREHOLDERS EQUITY
Retained Earnings $1.254B $2.093B $2.042B
YoY Change -40.09% -9.08% -29.92%
Common Stock $6.154B $5.967B $5.852B
YoY Change 3.13% 3.29% 3.16%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity $3.375B $4.151B $4.262B
YoY Change
Total Liabilities & Shareholders Equity $29.41B $26.42B $25.60B
YoY Change 11.29% 1.28% -1.24%

Cashflow Statement

Concept 2019 Q4 2018 Q4 2018 Q3
OPERATING ACTIVITIES
Net Income $382.0M $353.0M $153.0M
YoY Change 8.22% -3041.67% -20.31%
Depreciation, Depletion And Amortization $145.0M $151.0M $40.00M
YoY Change -3.97% 8.63% 0.0%
Cash From Operating Activities $672.0M $711.0M $562.0M
YoY Change -5.49% 86.61% -482.31%
INVESTING ACTIVITIES
Capital Expenditures -$58.00M -$61.00M -$68.00M
YoY Change -4.92% 5.17% 58.14%
Acquisitions
YoY Change
Other Investing Activities $60.00M $8.000M -$27.00M
YoY Change 650.0% -97.52% -102.51%
Cash From Investing Activities $2.000M -$53.00M -$95.00M
YoY Change -103.77% -120.0% -109.2%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities -525.0M -444.0M -457.0M
YoY Change 18.24% -28.04% -47.95%
NET CHANGE
Cash From Operating Activities 672.0M 711.0M 562.0M
Cash From Investing Activities 2.000M -53.00M -95.00M
Cash From Financing Activities -525.0M -444.0M -457.0M
Net Change In Cash 149.0M 214.0M 10.00M
YoY Change -30.37% 637.93% 25.0%
FREE CASH FLOW
Cash From Operating Activities $672.0M $711.0M $562.0M
Capital Expenditures -$58.00M -$61.00M -$68.00M
Free Cash Flow $730.0M $772.0M $630.0M
YoY Change -5.44% 75.85% -705.77%

Facts In Submission

Frame Concept Type Concept / XBRL Key Value Unit
CY2018 us-gaap Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount
AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
0 shares
CY2017 us-gaap Common Stock Dividends Per Share Declared
CommonStockDividendsPerShareDeclared
1.41
CY2018 us-gaap Common Stock Dividends Per Share Declared
CommonStockDividendsPerShareDeclared
1.56
CY2019 us-gaap Common Stock Dividends Per Share Declared
CommonStockDividendsPerShareDeclared
1.72
CY2018Q4 us-gaap Common Stock Par Or Stated Value Per Share
CommonStockParOrStatedValuePerShare
0.01
CY2018Q4 us-gaap Common Stock Shares Authorized
CommonStockSharesAuthorized
750000000 shares
CY2019Q4 us-gaap Common Stock Shares Authorized
CommonStockSharesAuthorized
750000000 shares
CY2018Q4 us-gaap Common Stock Shares Issued
CommonStockSharesIssued
240100000.0 shares
CY2019Q4 us-gaap Common Stock Shares Issued
CommonStockSharesIssued
232100000.0 shares
CY2019Q4 us-gaap Defined Benefit Plan Expected Future Benefit Payments Year Five
DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
5000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax
OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
0 USD
CY2019 dei Amendment Flag
AmendmentFlag
false
CY2019 dei Current Fiscal Year End Date
CurrentFiscalYearEndDate
--12-31
CY2019 dei Document Fiscal Period Focus
DocumentFiscalPeriodFocus
FY
CY2019 dei Document Fiscal Year Focus
DocumentFiscalYearFocus
2019
CY2019 dei Entity Address Country
EntityAddressCountry
GB
CY2019 dei Entity Central Index Key
EntityCentralIndexKey
0000315293
CY2019 dei Entity Incorporation State Country Code
EntityIncorporationStateCountryCode
X0
CY2017 us-gaap Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount
AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
0 shares
CY2019Q4 us-gaap Common Stock Par Or Stated Value Per Share
CommonStockParOrStatedValuePerShare
0.01
CY2018 us-gaap Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax
OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
0 USD
CY2019 dei Document Type
DocumentType
10-K
CY2019 dei Document Annual Report
DocumentAnnualReport
true
CY2019 dei Document Period End Date
DocumentPeriodEndDate
2019-12-31
CY2017 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
704000000 USD
CY2019 aon Other General Expenses
OtherGeneralExpenses
1393000000 USD
CY2018 aon Other General Expenses
OtherGeneralExpenses
1500000000 USD
CY2018 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
10770000000 USD
CY2017 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
9998000000 USD
CY2019 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6054000000 USD
CY2018 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6103000000 USD
CY2017 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6003000000 USD
CY2019 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
494000000 USD
CY2018 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
484000000 USD
CY2017 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
419000000 USD
CY2019 us-gaap Occupancy Net
OccupancyNet
339000000 USD
CY2018 us-gaap Occupancy Net
OccupancyNet
370000000 USD
CY2017 us-gaap Occupancy Net
OccupancyNet
348000000 USD
CY2019 us-gaap Depreciation
Depreciation
172000000 USD
CY2018 us-gaap Depreciation
Depreciation
176000000 USD
CY2017 us-gaap Depreciation
Depreciation
187000000 USD
CY2019 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
392000000 USD
CY2018 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
593000000 USD
CY2017 aon Other General Expenses
OtherGeneralExpenses
1272000000 USD
CY2018 us-gaap Costs And Expenses
CostsAndExpenses
9226000000 USD
CY2017 us-gaap Costs And Expenses
CostsAndExpenses
8933000000 USD
CY2019 us-gaap Operating Income Loss
OperatingIncomeLoss
2169000000 USD
CY2018 us-gaap Operating Income Loss
OperatingIncomeLoss
1544000000 USD
CY2017 us-gaap Operating Income Loss
OperatingIncomeLoss
1065000000 USD
CY2019 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
8000000 USD
CY2018 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
5000000 USD
CY2017 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
27000000 USD
CY2019 us-gaap Interest Expense
InterestExpense
307000000 USD
CY2018 us-gaap Interest Expense
InterestExpense
278000000 USD
CY2017 us-gaap Interest Expense
InterestExpense
282000000 USD
CY2019 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
1000000 USD
CY2018 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-25000000 USD
CY2017 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-125000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
1871000000 USD
CY2018 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
1246000000 USD
CY2017 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
685000000 USD
CY2019 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
297000000 USD
CY2018 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
40000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1574000000 USD
CY2018 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1100000000 USD
CY2017 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
435000000 USD
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-1000000 USD
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
74000000 USD
CY2017 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
828000000 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2019 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
41000000 USD
CY2018 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
40000000 USD
CY2017 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
37000000 USD
CY2019 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1532000000 USD
CY2018 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1134000000 USD
CY2017 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1226000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
6.42
CY2018 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
4.32
CY2017 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
1.54
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0.30
CY2017 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
3.20
CY2019 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
6.42
CY2018 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
4.62
CY2017 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
4.74
CY2019 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
6.37
CY2018 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
4.29
CY2017 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
1.53
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0.30
CY2019 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
6.37
CY2018 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
4.59
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2019 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
3000000 USD
CY2018Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
448000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
416000000 USD
CY2019 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
1408000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-19000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
-124000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
-416000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
421000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
0 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
-4000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
5000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-124000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-412000000 USD
CY2018 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
722000000 USD
CY2017 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
1642000000 USD
CY2019Q4 us-gaap Cash And Cash Equivalents At Carrying Value
CashAndCashEquivalentsAtCarryingValue
790000000 USD
CY2018Q4 us-gaap Cash And Cash Equivalents At Carrying Value
CashAndCashEquivalentsAtCarryingValue
656000000 USD
CY2019Q4 us-gaap Short Term Investments
ShortTermInvestments
138000000 USD
CY2018Q4 us-gaap Short Term Investments
ShortTermInvestments
172000000 USD
CY2019Q4 us-gaap Accounts Receivable Net Current
AccountsReceivableNetCurrent
3112000000 USD
CY2018Q4 us-gaap Accounts Receivable Net Current
AccountsReceivableNetCurrent
2760000000 USD
CY2019Q4 aon Fiduciary Assets
FiduciaryAssets
11834000000 USD
CY2018Q4 aon Fiduciary Assets
FiduciaryAssets
10166000000 USD
CY2019Q4 us-gaap Other Assets Current
OtherAssetsCurrent
602000000 USD
CY2018Q4 us-gaap Other Assets Current
OtherAssetsCurrent
618000000 USD
CY2019Q4 us-gaap Assets Current
AssetsCurrent
16476000000 USD
CY2018Q4 us-gaap Assets Current
AssetsCurrent
14372000000 USD
CY2019Q4 us-gaap Goodwill
Goodwill
8165000000 USD
CY2018Q4 us-gaap Goodwill
Goodwill
8171000000 USD
CY2019Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
783000000 USD
CY2018Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
1149000000 USD
CY2019Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
621000000 USD
CY2018Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
588000000 USD
CY2019Q4 us-gaap Operating Lease Right Of Use Asset
OperatingLeaseRightOfUseAsset
929000000 USD
CY2019Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
645000000 USD
CY2018Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
561000000 USD
CY2019Q4 us-gaap Defined Benefit Plan Assets For Plan Benefits Noncurrent
DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
1216000000 USD
CY2018Q4 us-gaap Defined Benefit Plan Assets For Plan Benefits Noncurrent
DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
1133000000 USD
CY2018Q4 us-gaap Common Stock Value
CommonStockValue
2000000 USD
CY2019Q4 us-gaap Liabilities
Liabilities
25956000000 USD
CY2018Q4 us-gaap Liabilities
Liabilities
22203000000 USD
CY2019Q4 us-gaap Common Stock Value
CommonStockValue
2000000 USD
CY2019Q4 aon Fiduciary Liabilities
FiduciaryLiabilities
11834000000 USD
CY2018Q4 aon Fiduciary Liabilities
FiduciaryLiabilities
10166000000 USD
CY2019Q4 us-gaap Operating Lease Liability Noncurrent
OperatingLeaseLiabilityNoncurrent
944000000 USD
CY2019Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
199000000 USD
CY2018Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
181000000 USD
CY2019Q4 us-gaap Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent
PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent
1738000000 USD
CY2018Q4 us-gaap Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent
PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent
1636000000 USD
CY2019Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
877000000 USD
CY2018Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
1097000000 USD
CY2019Q4 us-gaap Additional Paid In Capital Common Stock
AdditionalPaidInCapitalCommonStock
6152000000 USD
CY2018Q4 us-gaap Additional Paid In Capital Common Stock
AdditionalPaidInCapitalCommonStock
5965000000 USD
CY2019Q4 us-gaap Retained Earnings Accumulated Deficit
RetainedEarningsAccumulatedDeficit
1254000000 USD
CY2018Q4 us-gaap Retained Earnings Accumulated Deficit
RetainedEarningsAccumulatedDeficit
2093000000 USD
CY2019Q4 us-gaap Accumulated Other Comprehensive Income Loss Net Of Tax
AccumulatedOtherComprehensiveIncomeLossNetOfTax
-4033000000 USD
CY2018Q4 us-gaap Accumulated Other Comprehensive Income Loss Net Of Tax
AccumulatedOtherComprehensiveIncomeLossNetOfTax
-3909000000 USD
CY2019Q4 us-gaap Stockholders Equity
StockholdersEquity
3375000000 USD
CY2018Q4 us-gaap Stockholders Equity
StockholdersEquity
4151000000 USD
CY2019Q4 us-gaap Minority Interest
MinorityInterest
74000000 USD
CY2018Q4 us-gaap Minority Interest
MinorityInterest
68000000 USD
CY2019Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
3449000000 USD
CY2018Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
4219000000 USD
CY2019Q4 us-gaap Liabilities And Stockholders Equity
LiabilitiesAndStockholdersEquity
29405000000 USD
CY2018Q4 us-gaap Liabilities And Stockholders Equity
LiabilitiesAndStockholdersEquity
26422000000 USD
CY2016Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
5581000000 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2017 us-gaap Stock Issued During Period Value Share Based Compensation
StockIssuedDuringPeriodValueShareBasedCompensation
-121000000 USD
CY2017 us-gaap Stock Repurchased During Period Value
StockRepurchasedDuringPeriodValue
2415000000 USD
CY2017 us-gaap Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value
AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
321000000 USD
CY2018Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
4219000000 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
390000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-19000000 USD
CY2017 us-gaap Minority Interest Decrease From Redemptions
MinorityInterestDecreaseFromRedemptions
11000000 USD
CY2017 us-gaap Minority Interest Decrease From Distributions To Noncontrolling Interest Holders
MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
27000000 USD
CY2017Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
4648000000 USD
CY2018Q1 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest Adjusted Balance1
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1
5140000000 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2018 us-gaap Stock Issued During Period Value Share Based Compensation
StockIssuedDuringPeriodValueShareBasedCompensation
-148000000 USD
CY2018 us-gaap Stock Repurchased During Period Value
StockRepurchasedDuringPeriodValue
1454000000 USD
CY2018 us-gaap Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value
AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
338000000 USD
CY2018 us-gaap Dividends Common Stock Cash
DividendsCommonStockCash
382000000 USD
CY2018 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
11000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
-444000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-17000000 USD
CY2018 us-gaap Minority Interest Decrease From Redemptions
MinorityInterestDecreaseFromRedemptions
1000000 USD
CY2018 us-gaap Minority Interest Decrease From Distributions To Noncontrolling Interest Holders
MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
32000000 USD
CY2019 us-gaap Stock Issued During Period Value Share Based Compensation
StockIssuedDuringPeriodValueShareBasedCompensation
-131000000 USD
CY2019 us-gaap Stock Repurchased During Period Value
StockRepurchasedDuringPeriodValue
1960000000 USD
CY2019 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
3000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
14000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
141000000 USD
CY2019 us-gaap Minority Interest Decrease From Distributions To Noncontrolling Interest Holders
MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
35000000 USD
CY2019Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
3449000000 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-1000000 USD
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
74000000 USD
CY2017 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
828000000 USD
CY2019 aon Gain Loss On Saleof Business And Investments Net
GainLossOnSaleofBusinessAndInvestmentsNet
13000000 USD
CY2018 aon Gain Loss On Saleof Business And Investments Net
GainLossOnSaleofBusinessAndInvestmentsNet
-6000000 USD
CY2017 aon Gain Loss On Saleof Business And Investments Net
GainLossOnSaleofBusinessAndInvestmentsNet
-16000000 USD
CY2019 us-gaap Depreciation
Depreciation
172000000 USD
CY2018 us-gaap Depreciation
Depreciation
176000000 USD
CY2018 us-gaap Increase Decrease In Accounts Payable And Accrued Liabilities
IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
25000000 USD
CY2019 us-gaap Increase Decrease In Client Funds Held
IncreaseDecreaseInClientFundsHeld
1246000000 USD
CY2018 us-gaap Increase Decrease In Client Funds Held
IncreaseDecreaseInClientFundsHeld
320000000 USD
CY2017 us-gaap Increase Decrease In Client Funds Held
IncreaseDecreaseInClientFundsHeld
135000000 USD
CY2019 aon Increase Decrease In Fiduciary Liabilities
IncreaseDecreaseInFiduciaryLiabilities
1655000000 USD
CY2018 aon Increase Decrease In Fiduciary Liabilities
IncreaseDecreaseInFiduciaryLiabilities
999000000 USD
CY2017 aon Increase Decrease In Fiduciary Liabilities
IncreaseDecreaseInFiduciaryLiabilities
-36000000 USD
CY2019 us-gaap Increase Decrease In Receivables
IncreaseDecreaseInReceivables
371000000 USD
CY2018 us-gaap Increase Decrease In Receivables
IncreaseDecreaseInReceivables
127000000 USD
CY2017 us-gaap Increase Decrease In Receivables
IncreaseDecreaseInReceivables
254000000 USD
CY2019 us-gaap Increase Decrease In Accounts Payable And Accrued Liabilities
IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
-28000000 USD
CY2017 us-gaap Share Based Compensation
ShareBasedCompensation
319000000 USD
CY2019 us-gaap Deferred Income Taxes And Tax Credits
DeferredIncomeTaxesAndTaxCredits
-36000000 USD
CY2018 us-gaap Deferred Income Taxes And Tax Credits
DeferredIncomeTaxesAndTaxCredits
-225000000 USD
CY2017 us-gaap Deferred Income Taxes And Tax Credits
DeferredIncomeTaxesAndTaxCredits
-18000000 USD
CY2019 aon Increase Decrease In Fiduciary Receivables
IncreaseDecreaseInFiduciaryReceivables
409000000 USD
CY2018 aon Increase Decrease In Fiduciary Receivables
IncreaseDecreaseInFiduciaryReceivables
679000000 USD
CY2017 aon Increase Decrease In Fiduciary Receivables
IncreaseDecreaseInFiduciaryReceivables
-171000000 USD
CY2017 us-gaap Increase Decrease In Accounts Payable And Accrued Liabilities
IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
96000000 USD
CY2019 us-gaap Increase Decrease In Restructuring Reserve
IncreaseDecreaseInRestructuringReserve
3000000 USD
CY2017 us-gaap Increase Decrease In Restructuring Reserve
IncreaseDecreaseInRestructuringReserve
172000000 USD
CY2019 us-gaap Increase Decrease In Accrued Income Taxes Payable
IncreaseDecreaseInAccruedIncomeTaxesPayable
-20000000 USD
CY2017 us-gaap Increase Decrease In Pension And Postretirement Obligations
IncreaseDecreaseInPensionAndPostretirementObligations
-66000000 USD
CY2019 us-gaap Increase Decrease In Other Operating Capital Net
IncreaseDecreaseInOtherOperatingCapitalNet
-1000000 USD
CY2018 us-gaap Increase Decrease In Other Operating Capital Net
IncreaseDecreaseInOtherOperatingCapitalNet
-2000000 USD
CY2017 us-gaap Increase Decrease In Other Operating Capital Net
IncreaseDecreaseInOtherOperatingCapitalNet
8000000 USD
CY2019 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
1835000000 USD
CY2018 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
1686000000 USD
CY2017 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
669000000 USD
CY2019 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
0 USD
CY2017 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
65000000 USD
CY2019 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
1835000000 USD
CY2018 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
1686000000 USD
CY2019 dei Document Transition Report
DocumentTransitionReport
false
CY2019 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
61000000 USD
CY2018 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
71000000 USD
CY2017 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
68000000 USD
CY2019 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
113000000 USD
CY2018 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
80000000 USD
CY2017 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
64000000 USD
CY2019 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
-35000000 USD
CY2019 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
39000000 USD
CY2018 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
58000000 USD
CY2017 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
1029000000 USD
CY2019 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
52000000 USD
CY2018 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
-10000000 USD
CY2017 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
4246000000 USD
CY2019 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
225000000 USD
CY2018 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
240000000 USD
CY2017 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
183000000 USD
CY2019 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
-229000000 USD
CY2018 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
31000000 USD
CY2017 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
2806000000 USD
CY2019 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
0 USD
CY2017 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
-19000000 USD
CY2019 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
-229000000 USD
CY2018 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
31000000 USD
CY2017 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
2787000000 USD
CY2019 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
1960000000 USD
CY2018 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
149000000 USD
CY2017 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
121000000 USD
CY2019 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
6052000000 USD
CY2018 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
5754000000 USD
CY2017 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
1654000000 USD
CY2019 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
4941000000 USD
CY2018 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
5417000000 USD
CY2017 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
1999000000 USD
CY2019 dei Entity File Number
EntityFileNumber
1-7933
CY2019 dei Entity Registrant Name
EntityRegistrantName
Aon plc
CY2019 dei Entity Tax Identification Number
EntityTaxIdentificationNumber
98-1030901
CY2019 dei Entity Address Address Line1
EntityAddressAddressLine1
122 LEADENHALL STREET
CY2019 dei Entity Address City Or Town
EntityAddressCityOrTown
LONDON
CY2019 dei Entity Address Postal Zip Code
EntityAddressPostalZipCode
EC3V 4AN
CY2019 dei City Area Code
CityAreaCode
20
CY2019 dei Local Phone Number
LocalPhoneNumber
7623 5500
CY2019 dei Security12b Title
Security12bTitle
Class A Ordinary Shares, $0.01 nominal value
CY2019 dei Trading Symbol
TradingSymbol
AON
CY2019 dei Security Exchange Name
SecurityExchangeName
NYSE
CY2019 dei Entity Well Known Seasoned Issuer
EntityWellKnownSeasonedIssuer
Yes
CY2019 dei Entity Voluntary Filers
EntityVoluntaryFilers
No
CY2019 dei Entity Current Reporting Status
EntityCurrentReportingStatus
Yes
CY2019 dei Entity Interactive Data Current
EntityInteractiveDataCurrent
Yes
CY2019 dei Entity Filer Category
EntityFilerCategory
Large Accelerated Filer
CY2019 dei Entity Small Business
EntitySmallBusiness
false
CY2019 dei Entity Emerging Growth Company
EntityEmergingGrowthCompany
false
CY2019 dei Entity Shell Company
EntityShellCompany
false
CY2019Q2 dei Entity Public Float
EntityPublicFloat
45489377212 USD
CY2020Q1 dei Entity Common Stock Shares Outstanding
EntityCommonStockSharesOutstanding
231582094 shares
CY2019 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
11013000000 USD
CY2019 us-gaap Costs And Expenses
CostsAndExpenses
8844000000 USD
CY2018 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
146000000 USD
CY2017 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
250000000 USD
CY2017 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
3.17
CY2017 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
4.70
CY2019 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
238600000 shares
CY2018 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
245200000 shares
CY2017 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
258500000 shares
CY2019 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
240600000 shares
CY2018 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
247000000.0 shares
CY2017 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
260700000 shares
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2019 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
41000000 USD
CY2017 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
37000000 USD
CY2019 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1532000000 USD
CY2018 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1134000000 USD
CY2017 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1226000000 USD
CY2017 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
364000000 USD
CY2019 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
103000000 USD
CY2017 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
36000000 USD
CY2019 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-1493000000 USD
CY2018 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-1699000000 USD
CY2019 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2017 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2019 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-1493000000 USD
CY2018 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-1699000000 USD
CY2017 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-3265000000 USD
CY2019 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
21000000 USD
CY2018 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
-118000000 USD
CY2017 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
69000000 USD
CY2019 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
134000000 USD
CY2018 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
-100000000 USD
CY2017 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
325000000 USD
CY2018Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
656000000 USD
CY2017Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
756000000 USD
CY2016Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
431000000 USD
CY2019Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
790000000 USD
CY2018Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
656000000 USD
CY2017Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
756000000 USD
CY2019 us-gaap Interest Paid Net
InterestPaidNet
289000000 USD
CY2018 us-gaap Interest Paid Net
InterestPaidNet
266000000 USD
CY2017 us-gaap Interest Paid Net
InterestPaidNet
272000000 USD
CY2019 us-gaap Income Taxes Paid Net
IncomeTaxesPaidNet
353000000 USD
CY2019Q4 aon Restricted Cash Operating Funds
RestrictedCashOperatingFunds
55500000 USD
CY2018Q4 aon Restricted Cash Operating Funds
RestrictedCashOperatingFunds
42700000 GBP
CY2019Q4 aon Cashand Cash Equivalentsand Short Term Investments
CashandCashEquivalentsandShortTermInvestments
928000000 USD
CY2018Q4 aon Cashand Cash Equivalentsand Short Term Investments
CashandCashEquivalentsandShortTermInvestments
828000000 USD
CY2019Q4 us-gaap Restricted Cash And Investments Current
RestrictedCashAndInvestmentsCurrent
110000000 USD
CY2018Q4 us-gaap Restricted Cash And Investments Current
RestrictedCashAndInvestmentsCurrent
91000000 USD
CY2019Q4 aon Restricted Cash Operating Funds
RestrictedCashOperatingFunds
42700000 GBP
CY2018Q4 aon Restricted Cash Operating Funds
RestrictedCashOperatingFunds
53900000 USD
CY2019Q4 aon Fiduciary Assets Premium Trust Balances
FiduciaryAssetsPremiumTrustBalances
5200000000 USD
CY2018Q4 aon Fiduciary Assets Premium Trust Balances
FiduciaryAssetsPremiumTrustBalances
3900000000 USD
CY2019Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
70000000 USD
CY2018Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
62000000 USD
CY2019 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
11013000000 USD
CY2018 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
10770000000 USD
CY2019 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
1000000 USD
CY2018 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-25000000 USD
CY2017 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
9998000000 USD
CY2019 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
11013000000 USD
CY2018 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
10770000000 USD
CY2017 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
9998000000 USD
CY2019 us-gaap Foreign Currency Transaction Gain Loss Before Tax
ForeignCurrencyTransactionGainLossBeforeTax
9000000 USD
CY2018 us-gaap Foreign Currency Transaction Gain Loss Before Tax
ForeignCurrencyTransactionGainLossBeforeTax
25000000 USD
CY2017 us-gaap Foreign Currency Transaction Gain Loss Before Tax
ForeignCurrencyTransactionGainLossBeforeTax
-37000000 USD
CY2019 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
13000000 USD
CY2018 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
-6000000 USD
CY2017 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
-16000000 USD
CY2019 us-gaap Pension Expense
PensionExpense
-9000000 USD
CY2018 us-gaap Pension Expense
PensionExpense
-1000000 USD
CY2017 us-gaap Pension Expense
PensionExpense
86000000 USD
CY2019 us-gaap Income Loss From Equity Method Investments
IncomeLossFromEquityMethodInvestments
4000000 USD
CY2018 us-gaap Income Loss From Equity Method Investments
IncomeLossFromEquityMethodInvestments
4000000 USD
CY2017 us-gaap Income Loss From Equity Method Investments
IncomeLossFromEquityMethodInvestments
12000000 USD
CY2019 us-gaap Derivative Gain Loss On Derivative Net
DerivativeGainLossOnDerivativeNet
-34000000 USD
CY2018 us-gaap Derivative Gain Loss On Derivative Net
DerivativeGainLossOnDerivativeNet
-49000000 USD
CY2018Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
62000000 USD
CY2017Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
59000000 USD
CY2016Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
56000000 USD
CY2019 us-gaap Provision For Doubtful Accounts
ProvisionForDoubtfulAccounts
27000000 USD
CY2018 us-gaap Provision For Doubtful Accounts
ProvisionForDoubtfulAccounts
24000000 USD
CY2017 us-gaap Provision For Doubtful Accounts
ProvisionForDoubtfulAccounts
18000000 USD
CY2019 us-gaap Allowance For Doubtful Accounts Receivable Write Offs
AllowanceForDoubtfulAccountsReceivableWriteOffs
19000000 USD
CY2018 us-gaap Allowance For Doubtful Accounts Receivable Write Offs
AllowanceForDoubtfulAccountsReceivableWriteOffs
25000000 USD
CY2017 us-gaap Allowance For Doubtful Accounts Receivable Write Offs
AllowanceForDoubtfulAccountsReceivableWriteOffs
18000000 USD
CY2019 us-gaap Allowance For Doubtful Accounts Receivable Period Increase Decrease
AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
0 USD
CY2018 us-gaap Allowance For Doubtful Accounts Receivable Period Increase Decrease
AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
4000000 USD
CY2017 us-gaap Allowance For Doubtful Accounts Receivable Period Increase Decrease
AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
3000000 USD
CY2019Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
70000000 USD
CY2018Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
62000000 USD
CY2017Q4 us-gaap Allowance For Doubtful Accounts Receivable Current
AllowanceForDoubtfulAccountsReceivableCurrent
59000000 USD
CY2019Q4 us-gaap Contract With Customer Asset Net Current
ContractWithCustomerAssetNetCurrent
335000000 USD
CY2018Q4 us-gaap Contract With Customer Asset Net Current
ContractWithCustomerAssetNetCurrent
329000000 USD
CY2019Q4 aon Other Tax Assets Current
OtherTaxAssetsCurrent
88000000 USD
CY2018Q4 aon Other Tax Assets Current
OtherTaxAssetsCurrent
113000000 USD
CY2019Q4 us-gaap Prepaid Expense Current
PrepaidExpenseCurrent
97000000 USD
CY2018Q4 us-gaap Prepaid Expense Current
PrepaidExpenseCurrent
97000000 USD
CY2019Q4 us-gaap Disposal Group Including Discontinued Operation Accounts Notes And Loans Receivable Net
DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
4000000 USD
CY2018Q4 us-gaap Disposal Group Including Discontinued Operation Accounts Notes And Loans Receivable Net
DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
12000000 USD
CY2019Q4 us-gaap Other Assets Miscellaneous Current
OtherAssetsMiscellaneousCurrent
78000000 USD
CY2018Q4 us-gaap Other Assets Miscellaneous Current
OtherAssetsMiscellaneousCurrent
67000000 USD
CY2019Q4 us-gaap Other Assets Current
OtherAssetsCurrent
602000000 USD
CY2018Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
1097000000 USD
CY2019Q4 us-gaap Long Term Investments
LongTermInvestments
53000000 USD
CY2019Q4 us-gaap Property Plant And Equipment Gross
PropertyPlantAndEquipmentGross
1780000000 USD
CY2018Q4 us-gaap Property Plant And Equipment Gross
PropertyPlantAndEquipmentGross
1733000000 USD
CY2019Q4 us-gaap Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
1159000000 USD
CY2018Q4 us-gaap Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
1145000000 USD
CY2019Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
621000000 USD
CY2018Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
588000000 USD
CY2019 us-gaap Depreciation
Depreciation
172000000 USD
CY2018 us-gaap Depreciation
Depreciation
176000000 USD
CY2017 us-gaap Depreciation
Depreciation
187000000 USD
CY2019Q4 us-gaap Contract With Customer Asset Net Noncurrent
ContractWithCustomerAssetNetNoncurrent
171000000 USD
CY2018Q4 us-gaap Contract With Customer Asset Net Noncurrent
ContractWithCustomerAssetNetNoncurrent
156000000 USD
CY2018Q4 us-gaap Long Term Investments
LongTermInvestments
54000000 USD
CY2019Q4 us-gaap Finance Lease Right Of Use Asset
FinanceLeaseRightOfUseAsset
100000000 USD
CY2019Q4 us-gaap Income Taxes Receivable Noncurrent
IncomeTaxesReceivableNoncurrent
102000000 USD
CY2018Q4 us-gaap Income Taxes Receivable Noncurrent
IncomeTaxesReceivableNoncurrent
100000000 USD
CY2019Q4 us-gaap Other Assets Miscellaneous Noncurrent
OtherAssetsMiscellaneousNoncurrent
144000000 USD
CY2018Q4 us-gaap Other Assets Miscellaneous Noncurrent
OtherAssetsMiscellaneousNoncurrent
138000000 USD
CY2019Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
570000000 USD
CY2018Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
448000000 USD
CY2019Q4 us-gaap Tax Cuts And Jobs Act Of2017 Incomplete Accounting Transition Tax For Accumulated Foreign Earnings Provisional Liability Noncurrent
TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalLiabilityNoncurrent
145000000 USD
CY2018Q4 us-gaap Tax Cuts And Jobs Act Of2017 Incomplete Accounting Transition Tax For Accumulated Foreign Earnings Provisional Liability Noncurrent
TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalLiabilityNoncurrent
240000000 USD
CY2019Q4 us-gaap Contract With Customer Liability Current
ContractWithCustomerLiabilityCurrent
270000000 USD
CY2018Q4 us-gaap Accrued Income Taxes Noncurrent
AccruedIncomeTaxesNoncurrent
585000000 USD
CY2019Q4 us-gaap Finance Lease Liability Noncurrent
FinanceLeaseLiabilityNoncurrent
76000000 USD
CY2018Q4 us-gaap Contract With Customer Liability Current
ContractWithCustomerLiabilityCurrent
251000000 USD
CY2019Q4 us-gaap Accrued Income Taxes Current
AccruedIncomeTaxesCurrent
93000000 USD
CY2018Q4 us-gaap Capital Lease Obligations Noncurrent
CapitalLeaseObligationsNoncurrent
169000000 USD
CY2018Q4 us-gaap Accrued Income Taxes Current
AccruedIncomeTaxesCurrent
83000000 USD
CY2019Q4 aon Operating Lease And Finance Lease Liability Current
OperatingLeaseAndFinanceLeaseLiabilityCurrent
210000000 USD
CY2019Q4 us-gaap Other Accrued Liabilities Current
OtherAccruedLiabilitiesCurrent
513000000 USD
CY2018Q4 us-gaap Other Accrued Liabilities Current
OtherAccruedLiabilitiesCurrent
602000000 USD
CY2019Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
1086000000 USD
CY2018Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
936000000 USD
CY2019 us-gaap Contract With Customer Liability Revenue Recognized
ContractWithCustomerLiabilityRevenueRecognized
532000000 USD
CY2018 us-gaap Contract With Customer Liability Revenue Recognized
ContractWithCustomerLiabilityRevenueRecognized
487000000 USD
CY2019Q4 us-gaap Accrued Income Taxes Noncurrent
AccruedIncomeTaxesNoncurrent
525000000 USD
CY2019Q4 aon Employeerelated Liabilities Noncurrent
EmployeerelatedLiabilitiesNoncurrent
49000000 USD
CY2018Q4 aon Employeerelated Liabilities Noncurrent
EmployeerelatedLiabilitiesNoncurrent
56000000 USD
CY2019Q4 us-gaap Contract With Customer Liability Noncurrent
ContractWithCustomerLiabilityNoncurrent
62000000 USD
CY2018Q4 us-gaap Contract With Customer Liability Noncurrent
ContractWithCustomerLiabilityNoncurrent
65000000 USD
CY2019Q4 us-gaap Other Accrued Liabilities Noncurrent
OtherAccruedLiabilitiesNoncurrent
165000000 USD
CY2018Q4 us-gaap Other Accrued Liabilities Noncurrent
OtherAccruedLiabilitiesNoncurrent
222000000 USD
CY2018 us-gaap Goodwill Purchase Accounting Adjustments
GoodwillPurchaseAccountingAdjustments
4000000 USD
CY2017 us-gaap Restructuring And Related Cost Incurred Cost
RestructuringAndRelatedCostIncurredCost
497000000 USD
CY2019 us-gaap Number Of Businesses Acquired
NumberOfBusinessesAcquired
3
CY2018 us-gaap Number Of Businesses Acquired
NumberOfBusinessesAcquired
8
CY2019 us-gaap Acquired Finite Lived Intangible Assets Weighted Average Useful Life
AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife
P7Y
CY2019 us-gaap Business Combination Pro Forma Information Revenue Of Acquiree Since Acquisition Date Actual
BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
7000000 USD
CY2019 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
13000000 USD
CY2018 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
-6000000 USD
CY2017 us-gaap Disposal Group Not Discontinued Operation Gain Loss On Disposal
DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
-16000000 USD
CY2017Q4 us-gaap Goodwill
Goodwill
8358000000 USD
CY2018 us-gaap Goodwill Acquired During Period
GoodwillAcquiredDuringPeriod
38000000 USD
CY2018 us-gaap Goodwill Written Off Related To Sale Of Business Unit
GoodwillWrittenOffRelatedToSaleOfBusinessUnit
2000000 USD
CY2018 us-gaap Goodwill Foreign Currency Translation Gain Loss
GoodwillForeignCurrencyTranslationGainLoss
-227000000 USD
CY2018Q4 us-gaap Goodwill
Goodwill
8171000000 USD
CY2019 us-gaap Goodwill Acquired During Period
GoodwillAcquiredDuringPeriod
34000000 USD
CY2019 us-gaap Goodwill Written Off Related To Sale Of Business Unit
GoodwillWrittenOffRelatedToSaleOfBusinessUnit
11000000 USD
CY2019 us-gaap Goodwill Purchase Accounting Adjustments
GoodwillPurchaseAccountingAdjustments
2000000 USD
CY2019 us-gaap Goodwill Foreign Currency Translation Gain Loss
GoodwillForeignCurrencyTranslationGainLoss
-31000000 USD
CY2019Q4 us-gaap Goodwill
Goodwill
8165000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Gross
FiniteLivedIntangibleAssetsGross
3673000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Accumulated Amortization
FiniteLivedIntangibleAssetsAccumulatedAmortization
2890000000 USD
CY2019Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
783000000 USD
CY2018Q4 us-gaap Finite Lived Intangible Assets Gross
FiniteLivedIntangibleAssetsGross
3658000000 USD
CY2018Q4 us-gaap Finite Lived Intangible Assets Accumulated Amortization
FiniteLivedIntangibleAssetsAccumulatedAmortization
2509000000 USD
CY2018Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
1149000000 USD
CY2019 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
392000000 USD
CY2018 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
593000000 USD
CY2017 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
704000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense Next Twelve Months
FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
223000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense Year Two
FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
127000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense Year Three
FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
86000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense Year Four
FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
76000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense Year Five
FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
59000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Amortization Expense After Year Five
FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
212000000 USD
CY2019Q4 us-gaap Finite Lived Intangible Assets Net
FiniteLivedIntangibleAssetsNet
783000000 USD
CY2019Q4 us-gaap Finance Lease Right Of Use Asset
FinanceLeaseRightOfUseAsset
100000000 USD
CY2018Q4 us-gaap Debt Longterm And Shortterm Combined Amount
DebtLongtermAndShorttermCombinedAmount
6244000000 USD
CY2019Q4 us-gaap Debt Current
DebtCurrent
712000000 USD
CY2018Q4 us-gaap Debt Current
DebtCurrent
251000000 USD
CY2019Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
6627000000 USD
CY2018Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
5993000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal In Next Twelve Months
LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
712000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal In Year Two
LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
400000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal In Year Three
LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
500000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal In Year Four
LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
350000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal In Year Five
LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
600000000 USD
CY2019Q4 us-gaap Long Term Debt Maturities Repayments Of Principal After Year Five
LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
4882000000 USD
CY2019Q4 us-gaap Debt Instrument Carrying Amount
DebtInstrumentCarryingAmount
7444000000 USD
CY2019 aon Noncashpaymentoflongtermdebtnet
Noncashpaymentoflongtermdebtnet
105000000 USD
CY2019Q4 us-gaap Long Term Debt
LongTermDebt
7339000000 USD
CY2019 aon Debt Number Of Committed Credit Facilities
DebtNumberOfCommittedCreditFacilities
2 credit_facility
CY2019 us-gaap Short Term Lease Cost
ShortTermLeaseCost
5000000 USD
CY2019Q4 us-gaap Operating Lease Liability Current
OperatingLeaseLiabilityCurrent
186000000 USD
CY2019Q4 us-gaap Finance Lease Liability Current
FinanceLeaseLiabilityCurrent
24000000 USD
CY2019Q4 us-gaap Finance Lease Liability Noncurrent
FinanceLeaseLiabilityNoncurrent
76000000 USD
CY2019Q4 aon Operating And Finance Lease Liability
OperatingAndFinanceLeaseLiability
1230000000 USD
CY2019 us-gaap Operating Lease Cost
OperatingLeaseCost
234000000 USD
CY2019 us-gaap Finance Lease Right Of Use Asset Amortization
FinanceLeaseRightOfUseAssetAmortization
26000000 USD
CY2019 us-gaap Finance Lease Interest Expense
FinanceLeaseInterestExpense
2000000 USD
CY2019 us-gaap Variable Lease Cost
VariableLeaseCost
60000000 USD
CY2019 us-gaap Sublease Income
SubleaseIncome
32000000 USD
CY2019 us-gaap Lease Cost
LeaseCost
295000000 USD
CY2019Q4 us-gaap Operating Lease Weighted Average Remaining Lease Term1
OperatingLeaseWeightedAverageRemainingLeaseTerm1
P7Y10M24D
CY2019Q4 us-gaap Finance Lease Weighted Average Remaining Lease Term1
FinanceLeaseWeightedAverageRemainingLeaseTerm1
P4Y4M24D
CY2019Q4 us-gaap Lessee Operating Lease Discount Rate
LesseeOperatingLeaseDiscountRate
0.032
CY2019Q4 us-gaap Lessee Finance Lease Discount Rate
LesseeFinanceLeaseDiscountRate
0.020
CY2019 us-gaap Operating Lease Payments
OperatingLeasePayments
264000000 USD
CY2019 us-gaap Finance Lease Principal Payments
FinanceLeasePrincipalPayments
17000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due Next Twelve Months
LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
208000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due Next Twelve Months
FinanceLeaseLiabilityPaymentsDueNextTwelveMonths
26000000 USD
CY2019Q4 aon Finance And Operating Lease Liability Payments Net Of Sublease Income Remainder Of Fiscal Year
FinanceAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeRemainderOfFiscalYear
234000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due Year Two
LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
202000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due Year Two
FinanceLeaseLiabilityPaymentsDueYearTwo
26000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due Year Two
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDueYearTwo
228000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due Year Three
LesseeOperatingLeaseLiabilityPaymentsDueYearThree
177000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due Year Three
FinanceLeaseLiabilityPaymentsDueYearThree
20000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due Year Three
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDueYearThree
197000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due Year Four
LesseeOperatingLeaseLiabilityPaymentsDueYearFour
141000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due Year Four
FinanceLeaseLiabilityPaymentsDueYearFour
18000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due Year Four
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDueYearFour
159000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due
FinanceLeaseLiabilityPaymentsDue
105000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due After Year Five
FinanceLeaseLiabilityPaymentsDueAfterYearFive
0 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due After Year Five
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDueAfterYearFive
432000000 USD
CY2018Q4 aon Operating Lease Future Minimum Payments Due Future Minimum Sublease Rentals Year Four
OperatingLeaseFutureMinimumPaymentsDueFutureMinimumSubleaseRentalsYearFour
30000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals Due In Four Years
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentalsDueInFourYears
152000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due Year Five
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDueYearFive
128000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due After Year Five
LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
432000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Payments Net Of Sublease Income Due
FinancingAndOperatingLeaseLiabilityPaymentsNetOfSubleaseIncomeDue
1378000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Undiscounted Excess Amount
LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
143000000 USD
CY2019Q4 us-gaap Finance Lease Liability Undiscounted Excess Amount
FinanceLeaseLiabilityUndiscountedExcessAmount
5000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Net Of Sublease Income Undiscounted Excess Amount
FinancingAndOperatingLeaseLiabilityNetOfSubleaseIncomeUndiscountedExcessAmount
148000000 USD
CY2019Q4 us-gaap Operating Lease Liability
OperatingLeaseLiability
1130000000 USD
CY2019Q4 us-gaap Finance Lease Liability
FinanceLeaseLiability
100000000 USD
CY2019Q4 aon Financing And Operating Lease Liability Net Of Sublease Income
FinancingAndOperatingLeaseLiabilityNetOfSubleaseIncome
1230000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due Current
OperatingLeasesFutureMinimumPaymentsDueCurrent
303000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Due Future Sublease Rentals Next Twelve Months
OperatingLeasesFutureMinimumPaymentsDueFutureSubleaseRentalsNextTwelveMonths
34000000 USD
CY2018Q4 aon Operating Lease Future Minimum Payments Due Net Of Sublease Income Next Twelve Months
OperatingLeaseFutureMinimumPaymentsDueNetOfSubleaseIncomeNextTwelveMonths
269000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due In Two Years
OperatingLeasesFutureMinimumPaymentsDueInTwoYears
253000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Due Future Minimum Sublease Rentals Year Two
OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentalsYearTwo
30000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals Due In Two Years
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentalsDueInTwoYears
223000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due In Three Years
OperatingLeasesFutureMinimumPaymentsDueInThreeYears
221000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Due Future Sublease Rentals Year Three
OperatingLeasesFutureMinimumPaymentsDueFutureSubleaseRentalsYearThree
30000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals Due In Three Years
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentalsDueInThreeYears
191000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due In Four Years
OperatingLeasesFutureMinimumPaymentsDueInFourYears
182000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due In Five Years
OperatingLeasesFutureMinimumPaymentsDueInFiveYears
148000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Due Future Minimum Sublease Rentals Year Five
OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentalsYearFive
12000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals Due In Five Years
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentalsDueInFiveYears
136000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due Thereafter
OperatingLeasesFutureMinimumPaymentsDueThereafter
472000000 USD
CY2018Q4 aon Operating Lease Future Minimum Payments Due Future Minimum Sublease Rental Payments After Year Five
OperatingLeaseFutureMinimumPaymentsDueFutureMinimumSubleaseRentalPaymentsAfterYearFive
5000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals Due After Year Five
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentalsDueAfterYearFive
467000000 USD
CY2018Q4 us-gaap Operating Leases Future Minimum Payments Due
OperatingLeasesFutureMinimumPaymentsDue
1579000000 USD
CY2018Q4 aon Operating Lease Future Minimum Payments Due Future Minimum Sublease Rentals
OperatingLeaseFutureMinimumPaymentsDueFutureMinimumSubleaseRentals
141000000 USD
CY2018Q4 aon Operating Leases Future Minimum Payments Net Of Sublease Rentals
OperatingLeasesFutureMinimumPaymentsNetOfSubleaseRentals
1438000000 USD
CY2019 aon Income Loss From Continuing Operations Before Income Taxes
IncomeLossFromContinuingOperationsBeforeIncomeTaxes
1871000000 USD
CY2018 aon Income Loss From Continuing Operations Before Income Taxes
IncomeLossFromContinuingOperationsBeforeIncomeTaxes
1246000000 USD
CY2017 aon Income Loss From Continuing Operations Before Income Taxes
IncomeLossFromContinuingOperationsBeforeIncomeTaxes
685000000 USD
CY2018 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
11000000 USD
CY2017 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
12000000 USD
CY2018 us-gaap Adjustment For Amortization
AdjustmentForAmortization
593000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
14000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
-444000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
390000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
141000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-17000000 USD
CY2019Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
570000000 USD
CY2019Q4 us-gaap Assets
Assets
29405000000 USD
CY2018Q4 us-gaap Assets
Assets
26422000000 USD
CY2019Q4 us-gaap Accounts Payable And Accrued Liabilities Current
AccountsPayableAndAccruedLiabilitiesCurrent
1939000000 USD
CY2018Q4 us-gaap Accounts Payable And Accrued Liabilities Current
AccountsPayableAndAccruedLiabilitiesCurrent
1943000000 USD
CY2019Q4 us-gaap Debt Current
DebtCurrent
712000000 USD
CY2018Q4 us-gaap Debt Current
DebtCurrent
251000000 USD
CY2019Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
1086000000 USD
CY2018Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
936000000 USD
CY2019Q4 us-gaap Liabilities Current
LiabilitiesCurrent
15571000000 USD
CY2018Q4 us-gaap Liabilities Current
LiabilitiesCurrent
13296000000 USD
CY2019Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
6627000000 USD
CY2018Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
5993000000 USD
CY2017 us-gaap Dividends Common Stock Cash
DividendsCommonStockCash
364000000 USD
CY2017 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
12000000 USD
CY2018Q1 us-gaap Cumulative Effect Of New Accounting Principle In Period Of Adoption
CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
492000000 USD
CY2019 us-gaap Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value
AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
317000000 USD
CY2019 us-gaap Dividends Common Stock Cash
DividendsCommonStockCash
410000000 USD
CY2017 us-gaap Depreciation
Depreciation
187000000 USD
CY2019 us-gaap Adjustment For Amortization
AdjustmentForAmortization
392000000 USD
CY2017 us-gaap Adjustment For Amortization
AdjustmentForAmortization
704000000 USD
CY2019 us-gaap Share Based Compensation
ShareBasedCompensation
317000000 USD
CY2018 us-gaap Share Based Compensation
ShareBasedCompensation
338000000 USD
CY2018 us-gaap Increase Decrease In Restructuring Reserve
IncreaseDecreaseInRestructuringReserve
23000000 USD
CY2018 us-gaap Increase Decrease In Accrued Income Taxes Payable
IncreaseDecreaseInAccruedIncomeTaxesPayable
34000000 USD
CY2017 us-gaap Increase Decrease In Accrued Income Taxes Payable
IncreaseDecreaseInAccruedIncomeTaxesPayable
-914000000 USD
CY2019 us-gaap Increase Decrease In Pension And Postretirement Obligations
IncreaseDecreaseInPensionAndPostretirementObligations
-156000000 USD
CY2018 us-gaap Increase Decrease In Pension And Postretirement Obligations
IncreaseDecreaseInPensionAndPostretirementObligations
-259000000 USD
CY2017 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
734000000 USD
CY2018 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
-348000000 USD
CY2017 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
232000000 USD
CY2018 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
1470000000 USD
CY2017 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
2399000000 USD
CY2019 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
131000000 USD
CY2018 us-gaap Current Income Tax Expense Benefit
CurrentIncomeTaxExpenseBenefit
371000000 USD
CY2017 us-gaap Current Income Tax Expense Benefit
CurrentIncomeTaxExpenseBenefit
268000000 USD
CY2019 us-gaap Deferred Income Tax Expense Benefit
DeferredIncomeTaxExpenseBenefit
-36000000 USD
CY2018 us-gaap Deferred Income Tax Expense Benefit
DeferredIncomeTaxExpenseBenefit
-225000000 USD
CY2017 us-gaap Deferred Income Tax Expense Benefit
DeferredIncomeTaxExpenseBenefit
-18000000 USD
CY2019 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
297000000 USD
CY2018 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
146000000 USD
CY2017 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
250000000 USD
CY2019 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2018 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2017 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.193
CY2019 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2018 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2017 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.193
CY2019 us-gaap Effective Income Tax Rate Reconciliation State And Local Income Taxes
EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
0.005
CY2018 us-gaap Effective Income Tax Rate Reconciliation State And Local Income Taxes
EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
-0.004
CY2017 us-gaap Effective Income Tax Rate Reconciliation State And Local Income Taxes
EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
-0.015
CY2019 us-gaap Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential
EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential
-0.060
CY2018 us-gaap Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential
EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential
-0.073
CY2017 us-gaap Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential
EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential
-0.303
CY2019 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense
EffectiveIncomeTaxRateReconciliationNondeductibleExpense
0.016
CY2018 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense
EffectiveIncomeTaxRateReconciliationNondeductibleExpense
0.027
CY2017 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense
EffectiveIncomeTaxRateReconciliationNondeductibleExpense
0.034
CY2019 us-gaap Effective Income Tax Rate Reconciliation Prior Year Income Taxes
EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes
0.001
CY2018 us-gaap Effective Income Tax Rate Reconciliation Prior Year Income Taxes
EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes
0.009
CY2017 us-gaap Effective Income Tax Rate Reconciliation Prior Year Income Taxes
EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes
0.020
CY2019 us-gaap Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance
EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance
0.018
CY2018 us-gaap Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance
EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance
0.038
CY2017 us-gaap Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance
EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance
-0.018
CY2019 us-gaap Effective Income Tax Rate Reconciliation Tax Contingencies
EffectiveIncomeTaxRateReconciliationTaxContingencies
0.022
CY2018 us-gaap Effective Income Tax Rate Reconciliation Tax Contingencies
EffectiveIncomeTaxRateReconciliationTaxContingencies
0.009
CY2017 us-gaap Effective Income Tax Rate Reconciliation Tax Contingencies
EffectiveIncomeTaxRateReconciliationTaxContingencies
0.016
CY2019 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost
EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost
0.028
CY2018 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost
EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost
0.036
CY2017 us-gaap Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost
EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost
0.080
CY2019 us-gaap Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent
EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent
-0.003
CY2018 us-gaap Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent
EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent
0.071
CY2017 us-gaap Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent
EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent
0.512
CY2019 us-gaap Effective Income Tax Rate Reconciliation Disposition Of Business
EffectiveIncomeTaxRateReconciliationDispositionOfBusiness
0
CY2018 us-gaap Effective Income Tax Rate Reconciliation Disposition Of Business
EffectiveIncomeTaxRateReconciliationDispositionOfBusiness
-0.102
CY2019 us-gaap Effective Income Tax Rate Reconciliation Other Adjustments
EffectiveIncomeTaxRateReconciliationOtherAdjustments
-0.002
CY2018 us-gaap Effective Income Tax Rate Reconciliation Other Adjustments
EffectiveIncomeTaxRateReconciliationOtherAdjustments
-0.012
CY2017 us-gaap Effective Income Tax Rate Reconciliation Other Adjustments
EffectiveIncomeTaxRateReconciliationOtherAdjustments
0.006
CY2019 us-gaap Effective Income Tax Rate Continuing Operations
EffectiveIncomeTaxRateContinuingOperations
0.159
CY2018 us-gaap Effective Income Tax Rate Continuing Operations
EffectiveIncomeTaxRateContinuingOperations
0.117
CY2017 us-gaap Effective Income Tax Rate Continuing Operations
EffectiveIncomeTaxRateContinuingOperations
0.365
CY2019 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2017 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.193
CY2019Q4 aon Deferred Tax Assets Net Operating And Capital Loss Carryforwards And Tax Credit Carryforwards
DeferredTaxAssetsNetOperatingAndCapitalLossCarryforwardsAndTaxCreditCarryforwards
440000000 USD
CY2018Q4 aon Deferred Tax Assets Net Operating And Capital Loss Carryforwards And Tax Credit Carryforwards
DeferredTaxAssetsNetOperatingAndCapitalLossCarryforwardsAndTaxCreditCarryforwards
563000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits
DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
373000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits
DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
351000000 USD
CY2019Q4 aon Deferred Tax Assets Lease Liability
DeferredTaxAssetsLeaseLiability
247000000 USD
CY2019Q4 aon Deferred Tax Assets Accrued Interest
DeferredTaxAssetsAccruedInterest
116000000 USD
CY2018Q4 aon Deferred Tax Assets Accrued Interest
DeferredTaxAssetsAccruedInterest
0 USD
CY2019Q4 us-gaap Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other
DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther
68000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other
DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther
98000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Investments
DeferredTaxAssetsInvestments
28000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Investments
DeferredTaxAssetsInvestments
28000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Deferred Income
DeferredTaxAssetsDeferredIncome
24000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Deferred Income
DeferredTaxAssetsDeferredIncome
29000000 USD
CY2019Q4 aon Deferred Tax Assets Lease Guarantees
DeferredTaxAssetsLeaseGuarantees
3000000 USD
CY2018Q4 aon Deferred Tax Assets Lease Guarantees
DeferredTaxAssetsLeaseGuarantees
5000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Other
DeferredTaxAssetsOther
57000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Other
DeferredTaxAssetsOther
46000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Gross
DeferredTaxAssetsGross
1356000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Gross
DeferredTaxAssetsGross
1120000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Valuation Allowance
DeferredTaxAssetsValuationAllowance
200000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Valuation Allowance
DeferredTaxAssetsValuationAllowance
171000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Net
DeferredTaxAssetsNet
1156000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Net
DeferredTaxAssetsNet
949000000 USD
CY2019Q4 aon Deferred Tax Liabilities Intangible Assets And Property Plant And Equipment
DeferredTaxLiabilitiesIntangibleAssetsAndPropertyPlantAndEquipment
251000000 USD
CY2019Q4 aon Deferred Tax Liabilities Lease Rightof Use Asset
DeferredTaxLiabilitiesLeaseRightofUseAsset
219000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities Tax Deferred Income
DeferredTaxLiabilitiesTaxDeferredIncome
128000000 USD
CY2018Q4 us-gaap Deferred Tax Liabilities Tax Deferred Income
DeferredTaxLiabilitiesTaxDeferredIncome
143000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities Undistributed Foreign Earnings
DeferredTaxLiabilitiesUndistributedForeignEarnings
28000000 USD
CY2018Q4 us-gaap Deferred Tax Liabilities Undistributed Foreign Earnings
DeferredTaxLiabilitiesUndistributedForeignEarnings
30000000 USD
CY2018Q4 us-gaap Deferred Tax Liabilities Unrealized Currency Transaction Gains
DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains
26000000 USD
CY2019Q4 aon Deferred Tax Liabilities Other Accrued Expenses
DeferredTaxLiabilitiesOtherAccruedExpenses
25000000 USD
CY2018Q4 aon Deferred Tax Liabilities Other Accrued Expenses
DeferredTaxLiabilitiesOtherAccruedExpenses
36000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities Other
DeferredTaxLiabilitiesOther
33000000 USD
CY2018Q4 us-gaap Deferred Tax Liabilities Other
DeferredTaxLiabilitiesOther
24000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities
DeferredTaxLiabilities
710000000 USD
CY2018Q4 us-gaap Deferred Tax Liabilities
DeferredTaxLiabilities
569000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Liabilities Net
DeferredTaxAssetsLiabilitiesNet
446000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Liabilities Net
DeferredTaxAssetsLiabilitiesNet
380000000 USD
CY2019Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
645000000 USD
CY2018Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
561000000 USD
CY2019Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
199000000 USD
CY2018Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
181000000 USD
CY2019Q4 us-gaap Deferred Tax Assets Liabilities Net
DeferredTaxAssetsLiabilitiesNet
446000000 USD
CY2018Q4 us-gaap Deferred Tax Assets Liabilities Net
DeferredTaxAssetsLiabilitiesNet
380000000 USD
CY2019 us-gaap Valuation Allowance Deferred Tax Asset Change In Amount
ValuationAllowanceDeferredTaxAssetChangeInAmount
29000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities Undistributed Foreign Earnings
DeferredTaxLiabilitiesUndistributedForeignEarnings
28000000 USD
CY2019 aon Income Tax Holiday Income Tax Benefits
IncomeTaxHolidayIncomeTaxBenefits
90000000 USD
CY2018 aon Income Tax Holiday Income Tax Benefits
IncomeTaxHolidayIncomeTaxBenefits
77000000 USD
CY2017 aon Income Tax Holiday Income Tax Benefits
IncomeTaxHolidayIncomeTaxBenefits
45000000 USD
CY2019 us-gaap Income Tax Holiday Income Tax Benefits Per Share
IncomeTaxHolidayIncomeTaxBenefitsPerShare
0.37
CY2018 us-gaap Income Tax Holiday Income Tax Benefits Per Share
IncomeTaxHolidayIncomeTaxBenefitsPerShare
0.31
CY2017 us-gaap Income Tax Holiday Income Tax Benefits Per Share
IncomeTaxHolidayIncomeTaxBenefitsPerShare
0.17
CY2018 us-gaap Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations
UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
6000000 USD
CY2018Q4 us-gaap Unrecognized Tax Benefits
UnrecognizedTaxBenefits
279000000 USD
CY2017Q4 us-gaap Unrecognized Tax Benefits
UnrecognizedTaxBenefits
280000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions
UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions
23000000 USD
CY2018 us-gaap Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions
UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions
18000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions
UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions
12000000 USD
CY2018 us-gaap Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions
UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions
10000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions
UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
5000000 USD
CY2018 us-gaap Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions
UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
24000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities
UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities
5000000 USD
CY2018 us-gaap Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities
UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities
0 USD
CY2019 us-gaap Unrecognized Tax Benefits Increases Resulting From Acquisition
UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition
0 USD
CY2018 us-gaap Unrecognized Tax Benefits Increases Resulting From Acquisition
UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition
1000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations
UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
5000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Increases Resulting From Foreign Currency Translation
UnrecognizedTaxBenefitsIncreasesResultingFromForeignCurrencyTranslation
0 USD
CY2018 us-gaap Unrecognized Tax Benefits Increases Resulting From Foreign Currency Translation
UnrecognizedTaxBenefitsIncreasesResultingFromForeignCurrencyTranslation
0 USD
CY2019Q4 us-gaap Unrecognized Tax Benefits
UnrecognizedTaxBenefits
299000000 USD
CY2018Q4 us-gaap Unrecognized Tax Benefits
UnrecognizedTaxBenefits
279000000 USD
CY2019Q4 us-gaap Unrecognized Tax Benefits That Would Impact Effective Tax Rate
UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
248000000 USD
CY2018Q4 us-gaap Unrecognized Tax Benefits That Would Impact Effective Tax Rate
UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
228000000 USD
CY2017Q4 us-gaap Unrecognized Tax Benefits That Would Impact Effective Tax Rate
UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
219000000 USD
CY2019 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Expense
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
24000000 USD
CY2018 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Expense
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
22000000 USD
CY2017 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Expense
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
11000000 USD
CY2019Q4 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
99000000 USD
CY2018Q4 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
77000000 USD
CY2017Q4 us-gaap Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued
UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
55000000 USD
CY2019Q4 aon Distributable Reserves Available Amount
DistributableReservesAvailableAmount
32400000000 USD
CY2018Q4 aon Distributable Reserves Available Amount
DistributableReservesAvailableAmount
2200000000 USD
CY2019Q3 aon Distributable Reserves Available Amount
DistributableReservesAvailableAmount
31000000000 USD
CY2017Q2 us-gaap Stock Repurchase Program Authorized Amount1
StockRepurchaseProgramAuthorizedAmount1
15000000000.0 USD
us-gaap Treasury Stock Shares Acquired
TreasuryStockSharesAcquired
128700000 shares
us-gaap Treasury Stock Value Acquired Cost Method
TreasuryStockValueAcquiredCostMethod
13000000000.0 USD
CY2019 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
238600000 shares
CY2018 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
245200000 shares
CY2017 us-gaap Weighted Average Number Of Shares Outstanding Basic
WeightedAverageNumberOfSharesOutstandingBasic
258500000 shares
CY2019 us-gaap Incremental Common Shares Attributable To Share Based Payment Arrangements
IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
2000000.0 shares
CY2018 us-gaap Incremental Common Shares Attributable To Share Based Payment Arrangements
IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
1800000 shares
CY2017 us-gaap Incremental Common Shares Attributable To Share Based Payment Arrangements
IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
2200000 shares
CY2019 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
240600000 shares
CY2018 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
247000000.0 shares
CY2017 us-gaap Weighted Average Number Of Diluted Shares Outstanding
WeightedAverageNumberOfDilutedSharesOutstanding
260700000 shares
CY2019 us-gaap Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount
AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
0 shares
CY2019 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
410000000 USD
CY2018 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
382000000 USD
CY2017 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
364000000 USD
CY2019 us-gaap Common Stock Dividends Per Share Cash Paid
CommonStockDividendsPerShareCashPaid
1.72
CY2018 us-gaap Common Stock Dividends Per Share Cash Paid
CommonStockDividendsPerShareCashPaid
1.56
CY2017 us-gaap Common Stock Dividends Per Share Cash Paid
CommonStockDividendsPerShareCashPaid
1.41
CY2017 us-gaap Oci Before Reclassifications Before Tax Attributable To Parent
OciBeforeReclassificationsBeforeTaxAttributableToParent
195000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Before Reclassifications Tax
OtherComprehensiveIncomeLossBeforeReclassificationsTax
-47000000 USD
CY2017 us-gaap Oci Before Reclassifications Net Of Tax Attributable To Parent
OciBeforeReclassificationsNetOfTaxAttributableToParent
242000000 USD
CY2017 us-gaap Reclassification From Aoci Current Period Before Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
-227000000 USD
CY2017 us-gaap Reclassification From Aoci Current Period Tax
ReclassificationFromAociCurrentPeriodTax
-53000000 USD
CY2017 us-gaap Reclassification From Aoci Current Period Net Of Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
-174000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
416000000 USD
CY2018 us-gaap Oci Before Reclassifications Before Tax Attributable To Parent
OciBeforeReclassificationsBeforeTaxAttributableToParent
-576000000 USD
CY2018 us-gaap Oci Before Reclassifications Net Of Tax Attributable To Parent
OciBeforeReclassificationsNetOfTaxAttributableToParent
-533000000 USD
CY2018 us-gaap Reclassification From Aoci Current Period Before Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
-157000000 USD
CY2018 us-gaap Reclassification From Aoci Current Period Tax
ReclassificationFromAociCurrentPeriodTax
-36000000 USD
CY2018 us-gaap Reclassification From Aoci Current Period Net Of Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
-121000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-412000000 USD
CY2019 us-gaap Oci Before Reclassifications Before Tax Attributable To Parent
OciBeforeReclassificationsBeforeTaxAttributableToParent
-282000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Before Reclassifications Tax
OtherComprehensiveIncomeLossBeforeReclassificationsTax
-58000000 USD
CY2019 us-gaap Oci Before Reclassifications Net Of Tax Attributable To Parent
OciBeforeReclassificationsNetOfTaxAttributableToParent
-224000000 USD
CY2019 us-gaap Reclassification From Aoci Current Period Before Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
-123000000 USD
CY2019 us-gaap Reclassification From Aoci Current Period Tax
ReclassificationFromAociCurrentPeriodTax
-23000000 USD
CY2019 us-gaap Reclassification From Aoci Current Period Net Of Tax Attributable To Parent
ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
-100000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-124000000 USD
CY2019 us-gaap Defined Contribution Plan Cost Recognized
DefinedContributionPlanCostRecognized
164000000 USD
CY2018 us-gaap Defined Contribution Plan Cost Recognized
DefinedContributionPlanCostRecognized
168000000 USD
CY2017 us-gaap Defined Contribution Plan Cost Recognized
DefinedContributionPlanCostRecognized
173000000 USD
CY2019Q4 aon Defined Benefit Plan Percentage Of Total Pension Obligations
DefinedBenefitPlanPercentageOfTotalPensionObligations
0.91
CY2019 us-gaap Allocated Share Based Compensation Expense
AllocatedShareBasedCompensationExpense
317000000 USD
CY2018 us-gaap Allocated Share Based Compensation Expense
AllocatedShareBasedCompensationExpense
338000000 USD
CY2017 us-gaap Allocated Share Based Compensation Expense
AllocatedShareBasedCompensationExpense
319000000 USD
CY2019 us-gaap Employee Service Share Based Compensation Tax Benefit From Compensation Expense
EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
66000000 USD
CY2018 us-gaap Employee Service Share Based Compensation Tax Benefit From Compensation Expense
EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
74000000 USD
CY2017 us-gaap Employee Service Share Based Compensation Tax Benefit From Compensation Expense
EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
73000000 USD
CY2019 us-gaap Allocated Share Based Compensation Expense Net Of Tax
AllocatedShareBasedCompensationExpenseNetOfTax
251000000 USD
CY2018 us-gaap Allocated Share Based Compensation Expense Net Of Tax
AllocatedShareBasedCompensationExpenseNetOfTax
264000000 USD
CY2017 us-gaap Allocated Share Based Compensation Expense Net Of Tax
AllocatedShareBasedCompensationExpenseNetOfTax
246000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax
OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax
-9000000 USD
CY2018 us-gaap Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax
OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
-18000000 USD
CY2017 us-gaap Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax
OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
18000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax
OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax
-14000000 USD
CY2018 us-gaap Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net
DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
-11000000 USD
CY2017 us-gaap Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net
DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
-1000000 USD
CY2019 us-gaap Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months
CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
-11000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax
OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
0 USD
CY2019Q4 us-gaap Secured Debt Current
SecuredDebtCurrent
600000000 USD
CY2019Q4 us-gaap Shortterm Debt Fair Value
ShorttermDebtFairValue
614000000 USD
CY2018Q4 us-gaap Secured Debt Current
SecuredDebtCurrent
0 USD
CY2018Q4 us-gaap Shortterm Debt Fair Value
ShorttermDebtFairValue
0 USD
CY2019Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
6627000000 USD
CY2019Q4 us-gaap Long Term Debt Fair Value
LongTermDebtFairValue
7442000000 USD
CY2018Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
5993000000 USD
CY2018Q4 us-gaap Long Term Debt Fair Value
LongTermDebtFairValue
6159000000 USD
CY2019Q4 us-gaap Letters Of Credit Outstanding Amount
LettersOfCreditOutstandingAmount
73000000 USD
CY2018Q4 us-gaap Letters Of Credit Outstanding Amount
LettersOfCreditOutstandingAmount
83000000 USD
CY2018Q4 us-gaap Guarantee Obligations Maximum Exposure
GuaranteeObligationsMaximumExposure
103000000 USD
CY2019 us-gaap Number Of Reportable Segments
NumberOfReportableSegments
1 segment
CY2019 aon Numberof Revenue Lines
NumberofRevenueLines
5 revenue_line
CY2019 us-gaap Number Of Reportable Segments
NumberOfReportableSegments
1 segment
CY2019 aon Number Of Performance Metrics Measured
NumberOfPerformanceMetricsMeasured
4 metric
CY2019 us-gaap Number Of Reportable Segments
NumberOfReportableSegments
1 segment
CY2019Q4 aon Property Plant And Equipment And Operating Lease Right Of Use Asset After Accumulated Depreciationand Amortization
PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetAfterAccumulatedDepreciationandAmortization
1550000000 USD
CY2018Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
588000000 USD
CY2019Q1 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
3143000000 USD
CY2019Q2 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2606000000 USD
CY2019Q3 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2379000000 USD
CY2019Q4 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2885000000 USD
CY2019 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
11013000000 USD
CY2019Q1 us-gaap Operating Income Loss
OperatingIncomeLoss
872000000 USD
CY2019Q2 us-gaap Operating Income Loss
OperatingIncomeLoss
413000000 USD
CY2019Q3 us-gaap Operating Income Loss
OperatingIncomeLoss
360000000 USD
CY2019Q4 us-gaap Operating Income Loss
OperatingIncomeLoss
524000000 USD
CY2019 us-gaap Operating Income Loss
OperatingIncomeLoss
2169000000 USD
CY2019Q1 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
676000000 USD
CY2019Q2 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
287000000 USD
CY2019Q3 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
229000000 USD
CY2019 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
410000000 USD
CY2018 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
382000000 USD
CY2018 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
35000000 USD
CY2017 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-3265000000 USD
CY2018 us-gaap Income Taxes Paid Net
IncomeTaxesPaidNet
337000000 USD
CY2017 us-gaap Income Taxes Paid Net
IncomeTaxesPaidNet
1182000000 USD
CY2019 us-gaap Use Of Estimates
UseOfEstimates
<div style="line-height:120%;padding-top:10px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Use of Estimates</span></div><div style="line-height:120%;padding-bottom:10px;padding-top:10px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of the accompanying Consolidated Financial Statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosures of contingent assets and liabilities at the date of the Consolidated Financial Statements, and the reported amounts of reserves and expenses. These estimates and assumptions are based on management’s best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Management believes its estimates to be reasonable given the current facts available. Aon adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity markets, and foreign currency exchange rate movements increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in estimates resulting from continuing changes in the economic environment would, if applicable, be reflected in the Consolidated Financial Statements in future periods.</span></div>
CY2019 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1574000000 USD
CY2019Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
0 USD
CY2019Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
0 USD
CY2019Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-1000000 USD
CY2019Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
0 USD
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-1000000 USD
CY2019Q1 us-gaap Profit Loss
ProfitLoss
676000000 USD
CY2019Q2 us-gaap Profit Loss
ProfitLoss
287000000 USD
CY2019Q3 us-gaap Profit Loss
ProfitLoss
228000000 USD
CY2019Q4 us-gaap Profit Loss
ProfitLoss
382000000 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2019Q2 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
10000000 USD
CY2019Q3 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
6000000 USD
CY2019Q4 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
8000000 USD
CY2019 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
41000000 USD
CY2019Q1 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
659000000 USD
CY2019Q2 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
277000000 USD
CY2019Q3 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
222000000 USD
CY2019Q4 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
374000000 USD
CY2019 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1532000000 USD
CY2019Q1 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
2.72
CY2019Q2 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
1.15
CY2019Q3 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
0.94
CY2019Q4 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
1.59
CY2019 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
6.42
CY2019Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2019Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2019Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2019Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0
CY2019Q1 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
2.72
CY2019Q2 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
1.15
CY2019Q3 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
0.94
CY2019Q4 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
1.59
CY2019 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
6.42
CY2019Q1 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
2.70
CY2019Q2 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
1.14
CY2019Q3 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
0.93
CY2019Q4 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
1.58
CY2019Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2019Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2019Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2019Q1 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
2.70
CY2019Q2 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
1.14
CY2019Q3 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
0.93
CY2019Q4 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
1.58
CY2019 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
6.37
CY2018Q1 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
3090000000 USD
CY2018Q2 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2561000000 USD
CY2018Q3 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2349000000 USD
CY2018Q4 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
2770000000 USD
CY2018 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
10770000000 USD
CY2018Q1 us-gaap Operating Income Loss
OperatingIncomeLoss
799000000 USD
CY2018Q2 us-gaap Operating Income Loss
OperatingIncomeLoss
-16000000 USD
CY2018Q3 us-gaap Operating Income Loss
OperatingIncomeLoss
262000000 USD
CY2018Q4 us-gaap Operating Income Loss
OperatingIncomeLoss
499000000 USD
CY2018 us-gaap Operating Income Loss
OperatingIncomeLoss
1544000000 USD
CY2018Q1 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
604000000 USD
CY2018Q2 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
57000000 USD
CY2018Q3 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
155000000 USD
CY2018Q4 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
284000000 USD
CY2018 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1100000000 USD
CY2018Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
6000000 USD
CY2018Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
1000000 USD
CY2018Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-2000000 USD
CY2018Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
69000000 USD
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
74000000 USD
CY2018Q1 us-gaap Profit Loss
ProfitLoss
610000000 USD
CY2018Q2 us-gaap Profit Loss
ProfitLoss
58000000 USD
CY2018Q3 us-gaap Profit Loss
ProfitLoss
153000000 USD
CY2018Q4 us-gaap Profit Loss
ProfitLoss
353000000 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2018Q1 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
16000000 USD
CY2018Q3 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
6000000 USD
CY2018Q4 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
8000000 USD
CY2018 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
40000000 USD
CY2018Q2 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
48000000 USD
CY2018Q1 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
2.37
CY2018Q2 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
0.19
CY2018Q3 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
0.61
CY2018Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0.02
CY2018Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2018Q4 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
1.14
CY2018Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
-0.01
CY2018Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0.28
CY2018 us-gaap Income Loss From Continuing Operations Per Basic Share
IncomeLossFromContinuingOperationsPerBasicShare
4.32
CY2018Q1 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0.02
CY2018Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0.01
CY2018Q3 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
-0.01
CY2018Q4 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0.28
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Basic Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
0.30
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0.30
CY2018Q1 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
2.37
CY2018Q2 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
0.19
CY2018Q3 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
0.60
CY2018Q4 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
1.41
CY2018 us-gaap Earnings Per Share Diluted
EarningsPerShareDiluted
4.59
CY2018Q3 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
147000000 USD
CY2018Q4 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
345000000 USD
CY2018 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1134000000 USD
CY2018Q1 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
2.39
CY2018Q2 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
0.20
CY2018Q3 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
0.60
CY2018Q4 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
1.42
CY2018 us-gaap Earnings Per Share Basic
EarningsPerShareBasic
4.62
CY2018Q1 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
2.35
CY2018Q2 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
0.19
CY2018Q3 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
0.61
CY2018Q4 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
1.13
CY2018 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
4.29
CY2017 us-gaap Derivative Gain Loss On Derivative Net
DerivativeGainLossOnDerivativeNet
2000000 USD
CY2017 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-125000000 USD
CY2018Q4 us-gaap Other Assets Current
OtherAssetsCurrent
618000000 USD
CY2019Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
877000000 USD
CY2019Q4 us-gaap Debt Longterm And Shortterm Combined Amount
DebtLongtermAndShorttermCombinedAmount
7339000000 USD
CY2019Q4 us-gaap Operating Lease Right Of Use Asset
OperatingLeaseRightOfUseAsset
929000000 USD
CY2019Q4 aon Operating Lease And Finance Lease Rightof Use Asset
OperatingLeaseAndFinanceLeaseRightofUseAsset
1029000000 USD
CY2019Q4 us-gaap Operating Lease Liability Noncurrent
OperatingLeaseLiabilityNoncurrent
944000000 USD
CY2019 us-gaap Right Of Use Asset Obtained In Exchange For Operating Lease Liability
RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
155000000 USD
CY2019 us-gaap Right Of Use Asset Obtained In Exchange For Finance Lease Liability
RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability
48000000 USD
CY2019 aon Operating Lease Right Of Use Asset Amortization
OperatingLeaseRightOfUseAssetAmortization
195000000 USD
CY2019 aon Increase Decrease In Operating Lease Liabilities Noncurrent
IncreaseDecreaseInOperatingLeaseLiabilitiesNoncurrent
-70000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due Year Five
LesseeOperatingLeaseLiabilityPaymentsDueYearFive
113000000 USD
CY2019Q4 us-gaap Finance Lease Liability Payments Due Year Five
FinanceLeaseLiabilityPaymentsDueYearFive
15000000 USD
CY2019Q4 us-gaap Lessee Operating Lease Liability Payments Due
LesseeOperatingLeaseLiabilityPaymentsDue
1273000000 USD
CY2019 us-gaap Current Income Tax Expense Benefit
CurrentIncomeTaxExpenseBenefit
333000000 USD
CY2017 us-gaap Effective Income Tax Rate Reconciliation Disposition Of Business
EffectiveIncomeTaxRateReconciliationDispositionOfBusiness
0
CY2018 us-gaap Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
0.190
CY2018Q4 aon Deferred Tax Liabilities Intangible Assets And Property Plant And Equipment
DeferredTaxLiabilitiesIntangibleAssetsAndPropertyPlantAndEquipment
310000000 USD
CY2019Q4 us-gaap Deferred Tax Liabilities Unrealized Currency Transaction Gains
DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains
26000000 USD
CY2019 us-gaap Schedule Of Repurchase Agreements
ScheduleOfRepurchaseAgreements
<div style="line-height:120%;padding-bottom:10px;padding-top:10px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The following table summarizes the Company’s share repurchase activity (in millions, except per share data):</span></div><div style="line-height:120%;padding-bottom:10px;padding-top:10px;text-align:left;font-size:10pt;"><div style="padding-left:0px;text-indent:0px;line-height:normal;padding-top:10px;"><table cellpadding="0" cellspacing="0" style="font-family:Times New Roman;font-size:10pt;width:100%;border-collapse:collapse;text-align:left;"><tr><td colspan="9"/></tr><tr><td style="width:48%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:23%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:23%;"/><td style="width:1%;"/></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="7" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">Twelve months ended December 31</span></div></td></tr><tr><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">2019</span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">2018</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Shares repurchased</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>10.5</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>10.0</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Average price per share</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>186.33</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>143.94</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Costs recorded to retained earnings</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Total repurchase cost</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>1,950</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>1,447</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Additional associated costs</span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>10</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>7</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Total costs recorded to retained earnings</span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>1,960</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>1,454</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr></table></div><span style="font-family:inherit;font-size:10pt;"><br/></span></div>
CY2018 us-gaap Other Comprehensive Income Loss Before Reclassifications Tax
OtherComprehensiveIncomeLossBeforeReclassificationsTax
-43000000 USD
CY2019 us-gaap Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1
EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
P2Y1M6D
CY2019Q4 us-gaap Guarantee Obligations Maximum Exposure
GuaranteeObligationsMaximumExposure
110000000 USD
CY2019 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
11013000000 USD
CY2019 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6054000000 USD
CY2019 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
494000000 USD
CY2019 us-gaap Occupancy Net
OccupancyNet
339000000 USD
CY2019 us-gaap Depreciation
Depreciation
172000000 USD
CY2019 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
392000000 USD
CY2019 aon Other General Expenses
OtherGeneralExpenses
1393000000 USD
CY2019 us-gaap Costs And Expenses
CostsAndExpenses
8844000000 USD
CY2019 us-gaap Operating Income Loss
OperatingIncomeLoss
2169000000 USD
CY2019 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
8000000 USD
CY2019 us-gaap Interest Expense
InterestExpense
307000000 USD
CY2019 aon Intercompany Interest Expense Income
IntercompanyInterestExpenseIncome
0 USD
CY2019 aon Intercompany Other Income Expense Net
IntercompanyOtherIncomeExpenseNet
0 USD
CY2019 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
1000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
1871000000 USD
CY2019 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
297000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1574000000 USD
CY2018 us-gaap Occupancy Net
OccupancyNet
370000000 USD
CY2018 us-gaap Depreciation
Depreciation
176000000 USD
CY2018 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
593000000 USD
CY2018 aon Other General Expenses
OtherGeneralExpenses
1500000000 USD
CY2018 us-gaap Costs And Expenses
CostsAndExpenses
9226000000 USD
CY2018 us-gaap Operating Income Loss
OperatingIncomeLoss
1544000000 USD
CY2018 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
5000000 USD
CY2018 us-gaap Interest Expense
InterestExpense
278000000 USD
CY2018 aon Intercompany Interest Expense Income
IntercompanyInterestExpenseIncome
0 USD
CY2019 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
-1000000 USD
CY2019 aon Income Loss Before Equity Earnings Of Subsidiaries
IncomeLossBeforeEquityEarningsOfSubsidiaries
1573000000 USD
CY2019 aon Equity Earnings From Subsidiaries
EquityEarningsFromSubsidiaries
0 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2019 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
41000000 USD
CY2019 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1532000000 USD
CY2018 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
10770000000 USD
CY2018 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6103000000 USD
CY2018 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
484000000 USD
CY2018 aon Intercompany Other Income Expense Net
IntercompanyOtherIncomeExpenseNet
0 USD
CY2018 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-25000000 USD
CY2018 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
1246000000 USD
CY2018 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
146000000 USD
CY2018 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
1100000000 USD
CY2018 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
74000000 USD
CY2018 aon Income Loss Before Equity Earnings Of Subsidiaries
IncomeLossBeforeEquityEarningsOfSubsidiaries
1174000000 USD
CY2018 aon Equity Earnings From Subsidiaries
EquityEarningsFromSubsidiaries
0 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2018 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
40000000 USD
CY2018 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1134000000 USD
CY2017 us-gaap Revenue From Contract With Customer Excluding Assessed Tax
RevenueFromContractWithCustomerExcludingAssessedTax
9998000000 USD
CY2017 us-gaap Labor And Related Expense
LaborAndRelatedExpense
6003000000 USD
CY2017 us-gaap Information Technology And Data Processing
InformationTechnologyAndDataProcessing
419000000 USD
CY2017 us-gaap Occupancy Net
OccupancyNet
348000000 USD
CY2017 us-gaap Depreciation
Depreciation
187000000 USD
CY2017 aon Amortization And Impairment Of Intangible Assets
AmortizationAndImpairmentOfIntangibleAssets
704000000 USD
CY2017 aon Other General Expenses
OtherGeneralExpenses
1272000000 USD
CY2017 us-gaap Costs And Expenses
CostsAndExpenses
8933000000 USD
CY2017 us-gaap Operating Income Loss
OperatingIncomeLoss
1065000000 USD
CY2017 us-gaap Investment Income Interest And Dividend
InvestmentIncomeInterestAndDividend
27000000 USD
CY2017 us-gaap Interest Expense
InterestExpense
282000000 USD
CY2017 aon Intercompany Interest Expense Income
IntercompanyInterestExpenseIncome
0 USD
CY2017 aon Intercompany Other Income Expense Net
IntercompanyOtherIncomeExpenseNet
0 USD
CY2017 us-gaap Nonoperating Income Expense
NonoperatingIncomeExpense
-125000000 USD
CY2017 us-gaap Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments
IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
685000000 USD
CY2017 us-gaap Income Tax Expense Benefit
IncomeTaxExpenseBenefit
250000000 USD
CY2017 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
435000000 USD
CY2017 us-gaap Income Loss From Discontinued Operations Net Of Tax
IncomeLossFromDiscontinuedOperationsNetOfTax
828000000 USD
CY2017 aon Income Loss Before Equity Earnings Of Subsidiaries
IncomeLossBeforeEquityEarningsOfSubsidiaries
1263000000 USD
CY2017 aon Equity Earnings From Subsidiaries
EquityEarningsFromSubsidiaries
0 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2017 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
37000000 USD
CY2017 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1226000000 USD
CY2019 us-gaap Profit Loss
ProfitLoss
1573000000 USD
CY2019 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
41000000 USD
CY2019 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1532000000 USD
CY2019 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
3000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
14000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
141000000 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
-124000000 USD
CY2019 aon Equity Other Comprehensive Income Loss From Subsidiaries
EquityOtherComprehensiveIncomeLossFromSubsidiaries
0 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
0 USD
CY2019 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-124000000 USD
CY2019 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
1408000000 USD
CY2018 us-gaap Profit Loss
ProfitLoss
1174000000 USD
CY2018 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
40000000 USD
CY2018 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1134000000 USD
CY2018 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
11000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
-444000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-17000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
-416000000 USD
CY2018 aon Equity Other Comprehensive Income Loss From Subsidiaries
EquityOtherComprehensiveIncomeLossFromSubsidiaries
0 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
-4000000 USD
CY2018 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
-412000000 USD
CY2018 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
722000000 USD
CY2017 us-gaap Profit Loss
ProfitLoss
1263000000 USD
CY2017 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
37000000 USD
CY2017 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
1226000000 USD
CY2017 us-gaap Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax
OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
12000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
390000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax
OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
-19000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax
OtherComprehensiveIncomeLossNetOfTax
421000000 USD
CY2017 aon Equity Other Comprehensive Income Loss From Subsidiaries
EquityOtherComprehensiveIncomeLossFromSubsidiaries
0 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
5000000 USD
CY2017 us-gaap Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent
OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
416000000 USD
CY2017 us-gaap Comprehensive Income Net Of Tax
ComprehensiveIncomeNetOfTax
1642000000 USD
CY2019Q4 us-gaap Cash And Cash Equivalents At Carrying Value
CashAndCashEquivalentsAtCarryingValue
790000000 USD
CY2019Q4 us-gaap Short Term Investments
ShortTermInvestments
138000000 USD
CY2019Q4 us-gaap Accounts Receivable Net Current
AccountsReceivableNetCurrent
3112000000 USD
CY2019 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
21000000 USD
CY2019Q4 aon Fiduciary Assets
FiduciaryAssets
11834000000 USD
CY2019Q4 us-gaap Due From Related Parties Current
DueFromRelatedPartiesCurrent
0 USD
CY2019Q4 us-gaap Other Assets Current
OtherAssetsCurrent
602000000 USD
CY2019Q4 us-gaap Assets Current
AssetsCurrent
16476000000 USD
CY2019Q4 us-gaap Goodwill
Goodwill
8165000000 USD
CY2019Q4 us-gaap Due To Related Parties Current
DueToRelatedPartiesCurrent
0 USD
CY2019Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
1086000000 USD
CY2019Q4 us-gaap Liabilities Current
LiabilitiesCurrent
15571000000 USD
CY2019Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
6627000000 USD
CY2019Q4 us-gaap Operating Lease Liability Noncurrent
OperatingLeaseLiabilityNoncurrent
944000000 USD
CY2019Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
199000000 USD
CY2019Q4 us-gaap Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent
PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent
1738000000 USD
CY2019Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
783000000 USD
CY2019Q4 us-gaap Operating Lease Right Of Use Asset
OperatingLeaseRightOfUseAsset
929000000 USD
CY2019Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
621000000 USD
CY2019Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
645000000 USD
CY2019Q4 us-gaap Due From Related Parties Noncurrent
DueFromRelatedPartiesNoncurrent
0 USD
CY2019Q4 us-gaap Defined Benefit Plan Assets For Plan Benefits Noncurrent
DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
1216000000 USD
CY2019Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
570000000 USD
CY2019Q4 aon Investments In Subsidiaries
InvestmentsInSubsidiaries
0 USD
CY2019Q4 us-gaap Assets
Assets
29405000000 USD
CY2019Q4 us-gaap Accounts Payable And Accrued Liabilities Current
AccountsPayableAndAccruedLiabilitiesCurrent
1939000000 USD
CY2019Q4 us-gaap Debt Current
DebtCurrent
712000000 USD
CY2019Q4 aon Fiduciary Liabilities
FiduciaryLiabilities
11834000000 USD
CY2019Q4 us-gaap Due To Related Parties Noncurrent
DueToRelatedPartiesNoncurrent
0 USD
CY2019Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
877000000 USD
CY2019Q4 us-gaap Liabilities
Liabilities
25956000000 USD
CY2019Q4 us-gaap Stockholders Equity
StockholdersEquity
3375000000 USD
CY2019Q4 us-gaap Minority Interest
MinorityInterest
74000000 USD
CY2019Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
3449000000 USD
CY2019Q4 us-gaap Liabilities And Stockholders Equity
LiabilitiesAndStockholdersEquity
29405000000 USD
CY2018Q4 us-gaap Cash And Cash Equivalents At Carrying Value
CashAndCashEquivalentsAtCarryingValue
656000000 USD
CY2018Q4 us-gaap Short Term Investments
ShortTermInvestments
172000000 USD
CY2018Q4 us-gaap Accounts Receivable Net Current
AccountsReceivableNetCurrent
2760000000 USD
CY2018Q4 aon Fiduciary Assets
FiduciaryAssets
10166000000 USD
CY2018Q4 us-gaap Due From Related Parties Current
DueFromRelatedPartiesCurrent
0 USD
CY2018Q4 us-gaap Other Assets Current
OtherAssetsCurrent
618000000 USD
CY2018Q4 us-gaap Assets Current
AssetsCurrent
14372000000 USD
CY2018Q4 us-gaap Goodwill
Goodwill
8171000000 USD
CY2018Q4 us-gaap Intangible Assets Net Excluding Goodwill
IntangibleAssetsNetExcludingGoodwill
1149000000 USD
CY2018Q4 us-gaap Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
588000000 USD
CY2018Q4 us-gaap Deferred Income Tax Assets Net
DeferredIncomeTaxAssetsNet
561000000 USD
CY2018Q4 us-gaap Due From Related Parties Noncurrent
DueFromRelatedPartiesNoncurrent
0 USD
CY2018Q4 us-gaap Defined Benefit Plan Assets For Plan Benefits Noncurrent
DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
1133000000 USD
CY2018Q4 us-gaap Other Assets Noncurrent
OtherAssetsNoncurrent
448000000 USD
CY2018Q4 aon Investments In Subsidiaries
InvestmentsInSubsidiaries
0 USD
CY2018Q4 us-gaap Assets
Assets
26422000000 USD
CY2018Q4 us-gaap Accounts Payable And Accrued Liabilities Current
AccountsPayableAndAccruedLiabilitiesCurrent
1943000000 USD
CY2018Q4 us-gaap Debt Current
DebtCurrent
251000000 USD
CY2018Q4 aon Fiduciary Liabilities
FiduciaryLiabilities
10166000000 USD
CY2018Q4 us-gaap Due To Related Parties Current
DueToRelatedPartiesCurrent
0 USD
CY2018Q4 us-gaap Other Liabilities Current
OtherLiabilitiesCurrent
936000000 USD
CY2018Q4 us-gaap Liabilities Current
LiabilitiesCurrent
13296000000 USD
CY2018Q4 us-gaap Long Term Debt Noncurrent
LongTermDebtNoncurrent
5993000000 USD
CY2018Q4 us-gaap Deferred Income Tax Liabilities Net
DeferredIncomeTaxLiabilitiesNet
181000000 USD
CY2018Q4 us-gaap Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent
PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent
1636000000 USD
CY2018Q4 us-gaap Due To Related Parties Noncurrent
DueToRelatedPartiesNoncurrent
0 USD
CY2018Q4 us-gaap Other Liabilities Noncurrent
OtherLiabilitiesNoncurrent
1097000000 USD
CY2018Q4 us-gaap Liabilities
Liabilities
22203000000 USD
CY2018Q4 us-gaap Stockholders Equity
StockholdersEquity
4151000000 USD
CY2018Q4 us-gaap Minority Interest
MinorityInterest
68000000 USD
CY2018Q4 us-gaap Stockholders Equity Including Portion Attributable To Noncontrolling Interest
StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
4219000000 USD
CY2018Q4 us-gaap Liabilities And Stockholders Equity
LiabilitiesAndStockholdersEquity
26422000000 USD
CY2019 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
1835000000 USD
CY2019 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
0 USD
CY2019 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
1835000000 USD
CY2019 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
61000000 USD
CY2019 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
113000000 USD
CY2019 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
-35000000 USD
CY2019 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
39000000 USD
CY2019 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
52000000 USD
CY2019 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
225000000 USD
CY2019 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
-229000000 USD
CY2019 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
0 USD
CY2019 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
-229000000 USD
CY2019 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
1960000000 USD
CY2019 us-gaap Increase Decrease In Due To Affiliates
IncreaseDecreaseInDueToAffiliates
0 USD
CY2019 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
131000000 USD
CY2019 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
6052000000 USD
CY2019 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
4941000000 USD
CY2019 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
410000000 USD
CY2019 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
103000000 USD
CY2019 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-1493000000 USD
CY2019 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2019 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-1493000000 USD
CY2019 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
134000000 USD
CY2018Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
656000000 USD
CY2019Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
790000000 USD
CY2018 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
1686000000 USD
CY2018 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
1686000000 USD
CY2018 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
71000000 USD
CY2018 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
80000000 USD
CY2018 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
-348000000 USD
CY2018 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
58000000 USD
CY2018 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
-10000000 USD
CY2018 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
240000000 USD
CY2018 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
31000000 USD
CY2018 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
31000000 USD
CY2018 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
1470000000 USD
CY2018 us-gaap Increase Decrease In Due To Affiliates
IncreaseDecreaseInDueToAffiliates
0 USD
CY2018 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
149000000 USD
CY2018 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
5754000000 USD
CY2018 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
5417000000 USD
CY2018 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
382000000 USD
CY2018 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
35000000 USD
CY2018 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-1699000000 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2018 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-1699000000 USD
CY2018 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
-118000000 USD
CY2018 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
-100000000 USD
CY2017Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
756000000 USD
CY2018Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
656000000 USD
CY2017 us-gaap Net Cash Provided By Used In Operating Activities Continuing Operations
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
669000000 USD
CY2017 us-gaap Cash Provided By Used In Operating Activities Discontinued Operations
CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
65000000 USD
CY2017 us-gaap Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
734000000 USD
CY2017 us-gaap Proceeds From Sale And Maturity Of Other Investments
ProceedsFromSaleAndMaturityOfOtherInvestments
68000000 USD
CY2017 us-gaap Payments To Acquire Other Investments
PaymentsToAcquireOtherInvestments
64000000 USD
CY2017 aon Payments For Proceeds From Marketable Securities
PaymentsForProceedsFromMarketableSecurities
232000000 USD
CY2017 us-gaap Payments To Acquire Businesses Net Of Cash Acquired
PaymentsToAcquireBusinessesNetOfCashAcquired
1029000000 USD
CY2017 us-gaap Proceeds From Divestiture Of Businesses Net Of Cash Divested
ProceedsFromDivestitureOfBusinessesNetOfCashDivested
4246000000 USD
CY2017 us-gaap Payments To Acquire Property Plant And Equipment
PaymentsToAcquirePropertyPlantAndEquipment
183000000 USD
CY2017 us-gaap Net Cash Provided By Used In Investing Activities Continuing Operations
NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
2806000000 USD
CY2017 us-gaap Cash Provided By Used In Investing Activities Discontinued Operations
CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
-19000000 USD
CY2017 us-gaap Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInInvestingActivities
2787000000 USD
CY2017 us-gaap Payments For Repurchase Of Equity
PaymentsForRepurchaseOfEquity
2399000000 USD
CY2017 us-gaap Increase Decrease In Due To Affiliates
IncreaseDecreaseInDueToAffiliates
0 USD
CY2017 us-gaap Payments Related To Tax Withholding For Share Based Compensation
PaymentsRelatedToTaxWithholdingForShareBasedCompensation
121000000 USD
CY2017 us-gaap Proceeds From Issuance Of Long Term Debt
ProceedsFromIssuanceOfLongTermDebt
1654000000 USD
CY2017 us-gaap Repayments Of Long Term Debt
RepaymentsOfLongTermDebt
1999000000 USD
CY2017 us-gaap Payments Of Dividends Common Stock
PaymentsOfDividendsCommonStock
364000000 USD
CY2017 us-gaap Payments To Minority Shareholders
PaymentsToMinorityShareholders
36000000 USD
CY2017 us-gaap Net Cash Provided By Used In Financing Activities Continuing Operations
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
-3265000000 USD
CY2017 us-gaap Cash Provided By Used In Financing Activities Discontinued Operations
CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations
0 USD
CY2017 us-gaap Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInFinancingActivities
-3265000000 USD
CY2017 us-gaap Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents
EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
69000000 USD
CY2017 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
325000000 USD
CY2016Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
431000000 USD
CY2017Q4 us-gaap Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations
CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
756000000 USD
CY2016Q4 us-gaap Disposal Group Including Discontinued Operation Cash And Cash Equivalents
DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents
5000000 USD
CY2019Q4 us-gaap Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest
IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
382000000 USD
CY2019Q1 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
17000000 USD
CY2019 us-gaap Income Loss From Continuing Operations Per Diluted Share
IncomeLossFromContinuingOperationsPerDilutedShare
6.37
CY2019Q2 us-gaap Income Loss From Discontinued Operations Net Of Tax Per Diluted Share
IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
0
CY2018Q2 us-gaap Net Income Loss Attributable To Noncontrolling Interest
NetIncomeLossAttributableToNoncontrollingInterest
10000000 USD
CY2018Q1 us-gaap Net Income Loss Available To Common Stockholders Basic
NetIncomeLossAvailableToCommonStockholdersBasic
594000000 USD

Files In Submission

Name View Source Status
0001628280-20-001607-index-headers.html Edgar Link pending
0001628280-20-001607-index.html Edgar Link pending
0001628280-20-001607.txt Edgar Link pending
0001628280-20-001607-xbrl.zip Edgar Link pending
aon-20191231.xsd Edgar Link pending
aon-20191231_cal.xml Edgar Link unprocessable
aon-20191231_def.xml Edgar Link unprocessable
aon-20191231_lab.xml Edgar Link unprocessable
aon-20191231_pre.xml Edgar Link unprocessable
aonplc201910-k.htm Edgar Link pending
aonplc201910-k_htm.xml Edgar Link completed
exhibit10512019.htm Edgar Link pending
exhibit10582019.htm Edgar Link pending
exhibit10592019.htm Edgar Link pending
exhibit1060excessbenefit.htm Edgar Link pending
exhibit1060excessbenefit001.jpg Edgar Link pending
exhibit1060excessbenefit002.jpg Edgar Link pending
exhibit1060excessbenefit003.jpg Edgar Link pending
exhibit1060excessbenefit004.jpg Edgar Link pending
exhibit1060excessbenefit005.jpg Edgar Link pending
exhibit1060excessbenefit006.jpg Edgar Link pending
exhibit1060excessbenefit007.jpg Edgar Link pending
exhibit1060excessbenefit008.jpg Edgar Link pending
exhibit1060excessbenefit009.jpg Edgar Link pending
exhibit1060excessbenefit010.jpg Edgar Link pending
exhibit1060excessbenefit011.jpg Edgar Link pending
exhibit1060excessbenefit012.jpg Edgar Link pending
exhibit1060excessbenefit013.jpg Edgar Link pending
exhibit1060excessbenefit014.jpg Edgar Link pending
exhibit1060excessbenefit015.jpg Edgar Link pending
exhibit1060excessbenefit016.jpg Edgar Link pending
exhibit1060excessbenefit017.jpg Edgar Link pending
exhibit1060excessbenefit018.jpg Edgar Link pending
exhibit1060excessbenefit019.jpg Edgar Link pending
exhibit1060excessbenefit020.jpg Edgar Link pending
exhibit1060excessbenefit021.jpg Edgar Link pending
exhibit1060excessbenefit022.jpg Edgar Link pending
exhibit1060excessbenefit023.jpg Edgar Link pending
exhibit1060excessbenefit024.jpg Edgar Link pending
exhibit1060excessbenefit025.jpg Edgar Link pending
exhibit1060excessbenefit026.jpg Edgar Link pending
exhibit1060excessbenefit027.jpg Edgar Link pending
exhibit1060excessbenefit028.jpg Edgar Link pending
exhibit1060excessbenefit029.jpg Edgar Link pending
exhibit1072019.htm Edgar Link pending
exhibit212019.htm Edgar Link pending
exhibit23.htm Edgar Link pending
exhibit3112019.htm Edgar Link pending
exhibit3122019.htm Edgar Link pending
exhibit3212019.htm Edgar Link pending
exhibit3222019.htm Edgar Link pending
FilingSummary.xml Edgar Link unprocessable
Financial_Report.xlsx Edgar Link pending
g940964a40.jpg Edgar Link pending
MetaLinks.json Edgar Link pending
R1.htm Edgar Link pending
R10.htm Edgar Link pending
R100.htm Edgar Link pending
R101.htm Edgar Link pending
R102.htm Edgar Link pending
R103.htm Edgar Link pending
R104.htm Edgar Link pending
R105.htm Edgar Link pending
R106.htm Edgar Link pending
R107.htm Edgar Link pending
R108.htm Edgar Link pending
R109.htm Edgar Link pending
R11.htm Edgar Link pending
R110.htm Edgar Link pending
R111.htm Edgar Link pending
R112.htm Edgar Link pending
R113.htm Edgar Link pending
R114.htm Edgar Link pending
R115.htm Edgar Link pending
R116.htm Edgar Link pending
R117.htm Edgar Link pending
R118.htm Edgar Link pending
R119.htm Edgar Link pending
R12.htm Edgar Link pending
R120.htm Edgar Link pending
R121.htm Edgar Link pending
R122.htm Edgar Link pending
R123.htm Edgar Link pending
R124.htm Edgar Link pending
R125.htm Edgar Link pending
R126.htm Edgar Link pending
R127.htm Edgar Link pending
R128.htm Edgar Link pending
R129.htm Edgar Link pending
R13.htm Edgar Link pending
R130.htm Edgar Link pending
R131.htm Edgar Link pending
R132.htm Edgar Link pending
R133.htm Edgar Link pending
R14.htm Edgar Link pending
R15.htm Edgar Link pending
R16.htm Edgar Link pending
R17.htm Edgar Link pending
R18.htm Edgar Link pending
R19.htm Edgar Link pending
R2.htm Edgar Link pending
R20.htm Edgar Link pending
R21.htm Edgar Link pending
R22.htm Edgar Link pending
R23.htm Edgar Link pending
R24.htm Edgar Link pending
R25.htm Edgar Link pending
R26.htm Edgar Link pending
R27.htm Edgar Link pending
R28.htm Edgar Link pending
R29.htm Edgar Link pending
R3.htm Edgar Link pending
R30.htm Edgar Link pending
R31.htm Edgar Link pending
R32.htm Edgar Link pending
R33.htm Edgar Link pending
R34.htm Edgar Link pending
R35.htm Edgar Link pending
R36.htm Edgar Link pending
R37.htm Edgar Link pending
R38.htm Edgar Link pending
R39.htm Edgar Link pending
R4.htm Edgar Link pending
R40.htm Edgar Link pending
R41.htm Edgar Link pending
R42.htm Edgar Link pending
R43.htm Edgar Link pending
R44.htm Edgar Link pending
R45.htm Edgar Link pending
R46.htm Edgar Link pending
R47.htm Edgar Link pending
R48.htm Edgar Link pending
R49.htm Edgar Link pending
R5.htm Edgar Link pending
R50.htm Edgar Link pending
R51.htm Edgar Link pending
R52.htm Edgar Link pending
R53.htm Edgar Link pending
R54.htm Edgar Link pending
R55.htm Edgar Link pending
R56.htm Edgar Link pending
R57.htm Edgar Link pending
R58.htm Edgar Link pending
R59.htm Edgar Link pending
R6.htm Edgar Link pending
R60.htm Edgar Link pending
R61.htm Edgar Link pending
R62.htm Edgar Link pending
R63.htm Edgar Link pending
R64.htm Edgar Link pending
R65.htm Edgar Link pending
R66.htm Edgar Link pending
R67.htm Edgar Link pending
R68.htm Edgar Link pending
R69.htm Edgar Link pending
R7.htm Edgar Link pending
R70.htm Edgar Link pending
R71.htm Edgar Link pending
R72.htm Edgar Link pending
R73.htm Edgar Link pending
R74.htm Edgar Link pending
R75.htm Edgar Link pending
R76.htm Edgar Link pending
R77.htm Edgar Link pending
R78.htm Edgar Link pending
R79.htm Edgar Link pending
R8.htm Edgar Link pending
R80.htm Edgar Link pending
R81.htm Edgar Link pending
R82.htm Edgar Link pending
R83.htm Edgar Link pending
R84.htm Edgar Link pending
R85.htm Edgar Link pending
R86.htm Edgar Link pending
R87.htm Edgar Link pending
R88.htm Edgar Link pending
R89.htm Edgar Link pending
R9.htm Edgar Link pending
R90.htm Edgar Link pending
R91.htm Edgar Link pending
R92.htm Edgar Link pending
R93.htm Edgar Link pending
R94.htm Edgar Link pending
R95.htm Edgar Link pending
R96.htm Edgar Link pending
R97.htm Edgar Link pending
R98.htm Edgar Link pending
R99.htm Edgar Link pending
R9999.htm Edgar Link pending
report.css Edgar Link pending
Show.js Edgar Link pending