$MCO
MOODYS CORP /DE/ Stock $mco

$mco Overview Financials Valuation SEC Filings Company Website

2019 Q4 Form 10-K Financial Statement

#000105955620000005 Filed on February 24, 2020

Income Statement

Concept	2019 Q4	2019	2018 Q4
Revenue	$1.233B	$4.829B	$1.060B
YoY Change	16.32%	8.69%	-9.05%
Cost Of Revenue	$355.2M	$1.387B	$304.1M
YoY Change	16.8%	11.32%	-9.55%
Gross Profit	$877.6M	$3.442B	$756.0M
YoY Change	16.08%	7.66%	-8.84%
Gross Profit Margin	71.18%	71.28%	71.32%
Selling, General & Admin	$318.9M	$1.167B	$278.2M
YoY Change	14.63%	8.06%	-6.99%
% of Gross Profit	36.34%	33.9%	36.8%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$50.10M	$200.0M	$48.30M
YoY Change	3.73%	4.22%	-3.21%
% of Gross Profit	5.71%	5.81%	6.39%
Operating Expenses	$369.0M	$2.831B	$326.5M
YoY Change	13.02%	9.94%	-6.45%
Operating Profit	$504.0M	$1.998B	$376.0M
YoY Change	34.04%	6.96%	-19.23%
Interest Expense	-$23.00M	-$208.0M	-$72.40M
YoY Change	-68.23%	-3.26%	58.42%
% of Operating Profit	-4.56%	-10.41%	-19.26%
Other Income/Expense, Net	-$28.60M	-$188.0M	$17.40M
YoY Change	-264.37%	-4.08%	-182.46%
Pretax Income	$452.4M	$1.810B	$321.6M
YoY Change	40.67%	93.38%	-21.12%
Income Tax	$91.40M	$381.0M	$63.20M
% Of Pretax Income	20.2%	21.05%	19.65%
Net Earnings	$359.0M	$1.422B	$251.0M
YoY Change	43.03%	8.55%	884.31%
Net Earnings / Revenue	29.12%	29.45%	23.68%
Basic Earnings Per Share	$1.91	$7.51	$1.31
Diluted Earnings Per Share	$1.88	$7.42	$1.29
COMMON SHARES
Basic Shares Outstanding		189.3M shares	191.3M shares
Diluted Shares Outstanding		191.6M shares

Balance Sheet

Concept	2019 Q4	2019	2018 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$1.930B	$1.930B	$1.818B
YoY Change	6.16%	6.16%	53.68%
Cash & Equivalents	$1.832B	$1.832B	$1.685B
Short-Term Investments	$98.00M	$98.00M	$133.0M
Other Short-Term Assets	$330.0M	$330.0M	$282.0M
YoY Change	17.02%	17.02%	12.75%
Inventory
Prepaid Expenses	$71.00M		$67.00M
Receivables	$1.419B	$1.419B	$1.287B
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$3.679B	$3.679B	$3.387B
YoY Change	8.62%	8.62%	31.25%
LONG-TERM ASSETS
Property, Plant & Equipment	$292.0M	$748.0M	$320.0M
YoY Change	-8.75%	133.75%	-1.57%
Goodwill	$3.722B		$3.781B
YoY Change	-1.56%		0.75%
Intangibles	$1.498B		$1.566B
YoY Change	-4.34%		-4.02%
Long-Term Investments	$127.0M	$127.0M	$124.0M
YoY Change	2.42%	2.42%	2.48%
Other Assets	$389.0M	$372.0M	$275.0M
YoY Change	41.45%	37.78%	71.98%
Total Long-Term Assets	$6.586B	$6.586B	$5.668B
YoY Change	16.2%	7.28%	-0.74%
TOTAL ASSETS
Total Short-Term Assets	$3.679B	$3.679B	$3.387B
Total Long-Term Assets	$6.586B	$6.586B	$5.668B
Total Assets	$10.27B	$10.27B	$9.526B
YoY Change	7.76%	7.76%	10.84%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$38.00M	$38.00M	$30.00M
YoY Change	26.67%	26.67%	37.61%
Accrued Expenses	$608.0M	$608.0M	$452.0M
YoY Change	34.51%	34.51%	-14.72%
Deferred Revenue	$1.050B		$953.0M
YoY Change	10.18%		7.85%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change			-100.0%
Long-Term Debt Due	$0.00	$0.00	$450.0M
YoY Change	-100.0%	-100.0%	50.25%
Total Short-Term Liabilities	$1.912B	$1.912B	$2.099B
YoY Change	-8.91%	-8.91%	1.73%
LONG-TERM LIABILITIES
Long-Term Debt	$5.581B	$5.581B	$5.226B
YoY Change	6.79%	6.79%	2.25%
Other Long-Term Liabilities	$504.0M	$1.578B	$576.0M
YoY Change	-12.5%	32.27%	-13.25%
Total Long-Term Liabilities	$6.085B	$7.159B	$5.802B
YoY Change	4.88%	11.53%	0.47%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.912B	$1.912B	$2.099B
Total Long-Term Liabilities	$6.085B	$7.159B	$5.802B
Total Liabilities	$9.428B	$9.653B	$8.870B
YoY Change	6.29%	6.47%	1.85%
SHAREHOLDERS EQUITY
Retained Earnings	$9.656B		$8.594B
YoY Change	12.36%		15.12%
Common Stock	$645.0M		$604.0M
YoY Change	6.79%		13.53%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$9.250B		$8.313B
YoY Change	11.27%		1.96%
Treasury Stock Shares	155.2M shares		151.6M shares
Shareholders Equity	$612.0M	$612.0M	$459.0M
YoY Change
Total Liabilities & Shareholders Equity	$10.27B	$10.27B	$9.526B
YoY Change	7.76%	7.76%	10.84%

Cashflow Statement

Concept	2019 Q4	2019	2018 Q4
OPERATING ACTIVITIES
Net Income	$359.0M	$1.422B	$251.0M
YoY Change	43.03%	8.55%	884.31%
Depreciation, Depletion And Amortization	$50.10M	$200.0M	$48.30M
YoY Change	3.73%	4.22%	-3.21%
Cash From Operating Activities	$490.6M	$1.675B	$376.5M
YoY Change	30.31%	14.65%	-8.59%
INVESTING ACTIVITIES
Capital Expenditures	-$8.100M	$69.00M	-$27.50M
YoY Change	-70.55%	-24.18%	29.72%
Acquisitions		$162.0M
YoY Change		-43.94%
Other Investing Activities	$193.6M	$105.0M	-$265.1M
YoY Change	-173.03%	-133.23%	-3182.56%
Cash From Investing Activities	$185.5M	$36.00M	-$292.6M
YoY Change	-163.4%	-108.87%	2222.22%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$991.0M
YoY Change		388.18%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-46.00M	-$1.563B	568.7M
YoY Change	-108.09%	279.37%	-291.74%
NET CHANGE
Cash From Operating Activities	490.6M	$1.675B	376.5M
Cash From Investing Activities	185.5M	$36.00M	-292.6M
Cash From Financing Activities	-46.00M	-$1.563B	568.7M
Net Change In Cash	630.1M	$147.0M	652.6M
YoY Change	-3.45%	-76.02%	535.44%
FREE CASH FLOW
Cash From Operating Activities	$490.6M	$1.675B	$376.5M
Capital Expenditures	-$8.100M	$69.00M	-$27.50M
Free Cash Flow	$498.7M	$1.606B	$404.0M
YoY Change	23.44%	17.23%	-6.72%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2019	dei	Document Type DocumentType	10-K
CY2019	dei	Document Annual Report DocumentAnnualReport	true
CY2019	dei	Entity Address City Or Town EntityAddressCityOrTown	New York
CY2019	dei	Entity Address State Or Province EntityAddressStateOrProvince	NY
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Amendment Flag AmendmentFlag	false
CY2019	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
CY2019	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2019	dei	Entity Central Index Key EntityCentralIndexKey	0001059556
CY2019	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2019	dei	Document Transition Report DocumentTransitionReport	false
CY2019	dei	Entity File Number EntityFileNumber	1-14037
CY2019	dei	Entity Registrant Name EntityRegistrantName	MOODY’S CORPORATION
CY2019	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2019	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	13-3998945
CY2019	dei	Entity Address Address Line1 EntityAddressAddressLine1	7 World Trade Center at 250 Greenwich Street
CY2019	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	10007
CY2019	dei	City Area Code CityAreaCode	212
CY2019	dei	Local Phone Number LocalPhoneNumber	553-0300
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	37000000000.0	USD
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	187400000	shares
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019	us-gaap	Cost Of Revenue CostOfRevenue	1387000000	USD
CY2018	us-gaap	Cost Of Revenue CostOfRevenue	1246000000	USD
CY2017	us-gaap	Cost Of Revenue CostOfRevenue	1216000000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	1167000000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	1080000000	USD
CY2017	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	986000000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	60000000	USD
CY2018	us-gaap	Restructuring Charges RestructuringCharges	49000000	USD
CY2017	us-gaap	Restructuring Charges RestructuringCharges	0	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	200000000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	192000000	USD
CY2017	us-gaap	Depreciation And Amortization DepreciationAndAmortization	158000000	USD
CY2019	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	3000000	USD
CY2018	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	8000000	USD
CY2017	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	23000000	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-14000000	USD
CY2018	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2017	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Costs And Expenses CostsAndExpenses	2831000000	USD
CY2018	us-gaap	Costs And Expenses CostsAndExpenses	2575000000	USD
CY2017	us-gaap	Costs And Expenses CostsAndExpenses	2383000000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	1998000000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	1868000000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	1821000000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-208000000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-215000000	USD
CY2017	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-209000000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	20000000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	19000000	USD
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	4000000	USD
CY2019	mco	Realized Gain On Foreign Currency Purchase Price Hedge Derivatives RealizedGainOnForeignCurrencyPurchasePriceHedgeDerivatives	0	USD
CY2018	mco	Realized Gain On Foreign Currency Purchase Price Hedge Derivatives RealizedGainOnForeignCurrencyPurchasePriceHedgeDerivatives	0	USD
CY2017	mco	Realized Gain On Foreign Currency Purchase Price Hedge Derivatives RealizedGainOnForeignCurrencyPurchasePriceHedgeDerivatives	111000000	USD
CY2019	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	0	USD
CY2017	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	60000000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-188000000	USD
CY2018	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-196000000	USD
CY2017	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-34000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1810000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1672000000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1787000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	381000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	352000000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	779000000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1429000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	1320000000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	1008000000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	7000000	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	10000000	USD
CY2017	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	7000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	1422000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	1310000000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	1001000000	USD
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.51
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.84
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.24
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.42
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.74
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.15
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	189300000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	191600000	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	191100000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	191600000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	194400000	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	194200000	shares
CY2019	us-gaap	Profit Loss ProfitLoss	1429000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	1320000000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	1008000000	USD
CY2019	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification And Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationAndTax	-22000000	USD
CY2019	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationTax	1000000	USD
CY2019	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationNetOfTax	-23000000	USD
CY2018	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification And Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationAndTax	-315000000	USD
CY2018	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationTax	0	USD
CY2018	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationNetOfTax	-315000000	USD
CY2017	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification And Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationAndTax	225000000	USD
CY2017	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Before Reclassification Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentBeforeReclassificationNetOfTax	225000000	USD
CY2019	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentBeforeTax	-32000000	USD
CY2019	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentTax	0	USD
CY2019	us-gaap	Translation Adjustment Functional To Reporting Currency Gain Loss Reclassified To Earnings Net Of Tax TranslationAdjustmentFunctionalToReportingCurrencyGainLossReclassifiedToEarningsNetOfTax	-32000000	USD
CY2018	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentBeforeTax	0	USD
CY2018	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentTax	0	USD
CY2018	us-gaap	Translation Adjustment Functional To Reporting Currency Gain Loss Reclassified To Earnings Net Of Tax TranslationAdjustmentFunctionalToReportingCurrencyGainLossReclassifiedToEarningsNetOfTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentBeforeTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Foreign Currency Translation Reclassification Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationReclassificationAdjustmentTax	0	USD
CY2017	us-gaap	Translation Adjustment Functional To Reporting Currency Gain Loss Reclassified To Earnings Net Of Tax TranslationAdjustmentFunctionalToReportingCurrencyGainLossReclassifiedToEarningsNetOfTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationAndTax	35000000	USD
CY2019	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationTax	9000000	USD
CY2019	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Net Of Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationNetOfTax	26000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationAndTax	41000000	USD
CY2018	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationTax	7000000	USD
CY2018	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Net Of Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationNetOfTax	34000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationAndTax	-59000000	USD
CY2017	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationTax	-23000000	USD
CY2017	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Before Reclassification Net Of Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossBeforeReclassificationNetOfTax	-36000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax	3000000	USD
CY2019	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationTax	1000000	USD
CY2019	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Netof Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationNetofTax	2000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax	0	USD
CY2018	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationTax	0	USD
CY2018	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Netof Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationNetofTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Net Investment Hedge Gain Loss Reclassification Netof Tax OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationNetofTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	-1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-1000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	10000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	4000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	6000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	12000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	5000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	7000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	2000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax	2000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	4000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	3000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	2000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	5000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	4000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	8000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	3000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	5000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-32000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-8000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-24000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	6000000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	2000000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	4000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	21000000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	8000000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	13000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	13000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	2000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	11000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-264000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	10000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-274000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	191000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-13000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	204000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	1440000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	1046000000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	1212000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	11000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-12000000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	19000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1429000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1058000000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1193000000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1832000000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1685000000	USD
CY2019Q4	us-gaap	Short Term Investments ShortTermInvestments	98000000	USD
CY2018Q4	us-gaap	Short Term Investments ShortTermInvestments	133000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	43000000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	43000000	USD
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	1419000000	USD
CY2018Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	1287000000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	330000000	USD
CY2018Q4	us-gaap	Other Assets Current OtherAssetsCurrent	282000000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	3679000000	USD
CY2018Q4	us-gaap	Assets Current AssetsCurrent	3387000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	292000000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	320000000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	456000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	3722000000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	3781000000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	1498000000	USD
CY2018Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	1566000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	229000000	USD
CY2018Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	197000000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	389000000	USD
CY2018Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	275000000	USD
CY2019Q4	us-gaap	Assets Assets	10265000000	USD
CY2018Q4	us-gaap	Assets Assets	9526000000	USD
CY2019Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	773000000	USD
CY2018Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	696000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	89000000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2018Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	450000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	1050000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	953000000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	1912000000	USD
CY2018Q4	us-gaap	Liabilities Current LiabilitiesCurrent	2099000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	112000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	122000000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5581000000	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5226000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	357000000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	352000000	USD
CY2019Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	477000000	USD
CY2018Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	495000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	485000000	USD
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CY2018Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	576000000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	9428000000	USD
CY2018Q4	us-gaap	Liabilities Liabilities	8870000000	USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2018Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Redeemable Noncontrolling Interest Equity Carrying Amount RedeemableNoncontrollingInterestEquityCarryingAmount	6000000	USD
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CY2018Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000	shares
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CY2018Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
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CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2018Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
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CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2018Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2018Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	342902272	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	342902272	shares
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	3000000	USD
CY2018Q4	us-gaap	Common Stock Value CommonStockValue	3000000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	642000000	USD
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CY2018Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	8594000000	USD
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	155215143	shares
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CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	9250000000	USD
CY2018Q4	us-gaap	Treasury Stock Value TreasuryStockValue	8313000000	USD
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CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-426000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	612000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	459000000	USD
CY2019Q4	us-gaap	Minority Interest MinorityInterest	219000000	USD
CY2018Q4	us-gaap	Minority Interest MinorityInterest	197000000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	831000000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	656000000	USD
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CY2018Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	9526000000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1429000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	1320000000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	1008000000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	200000000	USD
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CY2017	us-gaap	Depreciation And Amortization DepreciationAndAmortization	158000000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	136000000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	130000000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	123000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-38000000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-99000000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	88000000	USD
CY2019	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	0	USD
CY2017	us-gaap	Gain Loss On Sale Of Stock In Subsidiary Or Equity Method Investee GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee	60000000	USD
CY2019	mco	Realized Gain On Foreign Currency Purchase Price Hedge Derivatives RealizedGainOnForeignCurrencyPurchasePriceHedgeDerivatives	0	USD
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CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-14000000	USD
CY2018	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2017	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	134000000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	136000000	USD
CY2017	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	148000000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	88000000	USD
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CY2019	us-gaap	Increase Decrease In Restructuring Reserve IncreaseDecreaseInRestructuringReserve	0	USD
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CY2019	mco	Increase Decreasein Contractwith Customer Liability Excluding Effectof Exchange Rate IncreaseDecreaseinContractwithCustomerLiabilityExcludingEffectofExchangeRate	76000000	USD
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CY2019	mco	Unrecognized Tax Benefits And Other Non Current Tax Liabilities Period Increase Decrease UnrecognizedTaxBenefitsAndOtherNonCurrentTaxLiabilitiesPeriodIncreaseDecrease	8000000	USD
CY2018	mco	Unrecognized Tax Benefits And Other Non Current Tax Liabilities Period Increase Decrease UnrecognizedTaxBenefitsAndOtherNonCurrentTaxLiabilitiesPeriodIncreaseDecrease	59000000	USD
CY2017	mco	Unrecognized Tax Benefits And Other Non Current Tax Liabilities Period Increase Decrease UnrecognizedTaxBenefitsAndOtherNonCurrentTaxLiabilitiesPeriodIncreaseDecrease	63000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	42000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-26000000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	263000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1675000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1461000000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	755000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	69000000	USD
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CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	91000000	USD
CY2019	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	138000000	USD
CY2018	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	193000000	USD
CY2017	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	170000000	USD
CY2019	us-gaap	Proceeds From Sale Maturity And Collection Of Shortterm Investments ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments	174000000	USD
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CY2017	us-gaap	Proceeds From Sale Maturity And Collection Of Shortterm Investments ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments	239000000	USD
CY2019	us-gaap	Proceeds From Derivative Instrument Investing Activities ProceedsFromDerivativeInstrumentInvestingActivities	0	USD
CY2018	us-gaap	Proceeds From Derivative Instrument Investing Activities ProceedsFromDerivativeInstrumentInvestingActivities	0	USD
CY2017	us-gaap	Proceeds From Derivative Instrument Investing Activities ProceedsFromDerivativeInstrumentInvestingActivities	111000000	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	226000000	USD
CY2018	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	6000000	USD
CY2017	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	162000000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	289000000	USD
CY2017	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	3511000000	USD
CY2019	us-gaap	Proceeds From Hedge Investing Activities ProceedsFromHedgeInvestingActivities	12000000	USD
CY2018	us-gaap	Proceeds From Hedge Investing Activities ProceedsFromHedgeInvestingActivities	0	USD
CY2017	us-gaap	Proceeds From Hedge Investing Activities ProceedsFromHedgeInvestingActivities	2000000	USD
CY2019	us-gaap	Payments For Hedge Investing Activities PaymentsForHedgeInvestingActivities	7000000	USD
CY2018	us-gaap	Payments For Hedge Investing Activities PaymentsForHedgeInvestingActivities	0	USD
CY2017	us-gaap	Payments For Hedge Investing Activities PaymentsForHedgeInvestingActivities	0	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	36000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-406000000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-3420000000	USD
CY2019	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	824000000	USD
CY2018	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	1090000000	USD
CY2017	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	2292000000	USD
CY2019	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	950000000	USD
CY2018	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	800000000	USD
CY2017	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	300000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Commercial Paper ProceedsFromIssuanceOfCommercialPaper	1317000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Commercial Paper ProceedsFromIssuanceOfCommercialPaper	989000000	USD
CY2017	us-gaap	Proceeds From Issuance Of Commercial Paper ProceedsFromIssuanceOfCommercialPaper	1837000000	USD
CY2019	us-gaap	Repayments Of Commercial Paper RepaymentsOfCommercialPaper	1320000000	USD
CY2018	us-gaap	Repayments Of Commercial Paper RepaymentsOfCommercialPaper	1120000000	USD
CY2017	us-gaap	Repayments Of Commercial Paper RepaymentsOfCommercialPaper	1707000000	USD
CY2019	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	45000000	USD
CY2018	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	47000000	USD
CY2017	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	56000000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	77000000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	62000000	USD
CY2017	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	49000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	991000000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	203000000	USD
CY2017	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	200000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	378000000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	337000000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	290000000	USD
CY2019	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	3000000	USD
CY2018	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	5000000	USD
CY2017	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	3000000	USD
CY2019	mco	Cash Paid Resulting In Reduction Of Noncontrolling Interest Ownership CashPaidResultingInReductionOfNoncontrollingInterestOwnership	12000000	USD
CY2018	mco	Cash Paid Resulting In Reduction Of Noncontrolling Interest Ownership CashPaidResultingInReductionOfNoncontrollingInterestOwnership	0	USD
CY2017	mco	Cash Paid Resulting In Reduction Of Noncontrolling Interest Ownership CashPaidResultingInReductionOfNoncontrollingInterestOwnership	9000000	USD
CY2019	mco	Payments Of Debt Issuance And Debt Extinguishment Or Debt Prepayment Costs PaymentsOfDebtIssuanceAndDebtExtinguishmentOrDebtPrepaymentCosts	18000000	USD
CY2018	mco	Payments Of Debt Issuance And Debt Extinguishment Or Debt Prepayment Costs PaymentsOfDebtIssuanceAndDebtExtinguishmentOrDebtPrepaymentCosts	11000000	USD
CY2017	mco	Payments Of Debt Issuance And Debt Extinguishment Or Debt Prepayment Costs PaymentsOfDebtIssuanceAndDebtExtinguishmentOrDebtPrepaymentCosts	27000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-1563000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-412000000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1600000000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-1000000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-30000000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	85000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	147000000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	613000000	USD
CY2017	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-980000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1685000000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1072000000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2052000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1832000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1685000000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1072000000	USD
CY2016Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-1027000000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	1008000000	USD
CY2017	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.14
CY2017	us-gaap	Dividends Dividends	223000000	USD
CY2017	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	123000000	USD
CY2017	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	10000000	USD
CY2017	us-gaap	Minority Interest Decrease From Redemptions MinorityInterestDecreaseFromRedemptions	5000000	USD
CY2017	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	200000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	23000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	189000000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	8000000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	13000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	3000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	5000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-2000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	1000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-1000000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-115000000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-115000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	1320000000	USD
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.76
CY2018	us-gaap	Dividends Dividends	343000000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	131000000	USD
CY2018	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-16000000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	203000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	7000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-281000000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	2000000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	4000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	4000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-1000000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	656000000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	656000000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1429000000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.00
CY2019	us-gaap	Dividends Dividends	383000000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	136000000	USD
CY2019	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-32000000	USD
CY2019	us-gaap	Minority Interest Decrease From Redemptions MinorityInterestDecreaseFromRedemptions	12000000	USD
CY2019	us-gaap	Noncontrolling Interest Increase From Business Combination NoncontrollingInterestIncreaseFromBusinessCombination	17000000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	991000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	9000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	33000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-8000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-24000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	2000000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	831000000	USD
CY2019	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2019	us-gaap	Number Of Reporting Units NumberOfReportingUnits	7	reportingUnit
CY2019	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="margin-top:6pt;margin-bottom:6pt;"><span style="background-color:rgb(255,255,255, 0.0);color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:700;line-height:120%;">Concentration of Credit Risk</span></div><div style="margin-top:6pt;margin-bottom:6pt;"><span style="background-color:rgb(255,255,255, 0.0);color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:120%;">Financial instruments that potentially subject the Company to concentration of credit risk principally consist of cash and cash equivalents, short-term investments, trade receivables and derivatives.</span></div>The Company manages its credit risk exposure by allocating its cash equivalents among various money market mutual funds, money market deposit accounts, certificates of deposits and high-grade commercial paper. Short-term investments primarily consist of certificates of deposit as of December 31, 2019 and 2018. The Company manages its credit risk exposure on cash equivalents and short-term investments by limiting the amount it can invest with any single entity.
CY2019	us-gaap	Use Of Estimates UseOfEstimates	Use of EstimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the period. Actual results could differ from those estimates.
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019	mco	Percentage Of Revenues PercentageOfRevenues	1
CY2018	mco	Percentage Of Revenues PercentageOfRevenues	1
CY2017	mco	Percentage Of Revenues PercentageOfRevenues	1
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1075000000	USD
CY2019	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	923000000	USD
CY2019	us-gaap	Contract With Customer Liability Cumulative Catch Up Adjustment To Revenue Change In Measure Of Progress ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInMeasureOfProgress	991000000	USD
CY2019	us-gaap	Contract With Customer Liability Increase Decrease For Contract Acquired In Business Combination ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination	9000000	USD
CY2019	mco	Effect Of Exchange Rate On Deferred Revenue EffectOfExchangeRateOnDeferredRevenue	10000000	USD
CY2019	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	87000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1162000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	1050000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	112000000	USD
CY2017Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	946000000	USD
CY2018	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	808000000	USD
CY2018	us-gaap	Contract With Customer Liability Cumulative Catch Up Adjustment To Revenue Change In Measure Of Progress ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInMeasureOfProgress	946000000	USD
CY2018	us-gaap	Contract With Customer Liability Increase Decrease For Contract Acquired In Business Combination ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination	16000000	USD
CY2018	mco	Effect Of Exchange Rate On Deferred Revenue EffectOfExchangeRateOnDeferredRevenue	-25000000	USD
CY2018	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	129000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1075000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	953000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	122000000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	189300000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	191600000	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	191100000	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	2300000	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	2800000	shares
CY2017	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	3100000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	191600000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	194400000	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	194200000	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	200000	shares
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	400000	shares
CY2017	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	600000	shares
CY2019	us-gaap	Accelerated Share Repurchases Final Price Paid Per Share AcceleratedShareRepurchasesFinalPricePaidPerShare	180.33
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-208000000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-215000000	USD
CY2017	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-209000000	USD
CY2019	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossBeforeReclassificationAfterTax	26000000	USD
CY2018	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossBeforeReclassificationAfterTax	34000000	USD
CY2017	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossBeforeReclassificationAfterTax	-30000000	USD
CY2019	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossReclassificationAfterTax	2000000	USD
CY2018	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossReclassificationAfterTax	0	USD
CY2017	mco	Other Comprehensive Income Loss Cash Flow Hedgeand Net Investment Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeandNetInvestmentHedgeGainLossReclassificationAfterTax	7000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Derivative Excluded Component Increase Decrease After Adjustments And Tax OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsAndTax	52000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Derivative Excluded Component Increase Decrease After Adjustments And Tax OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsAndTax	11000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Derivative Excluded Component Increase Decrease After Adjustments And Tax OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsAndTax	0	USD
CY2019	us-gaap	Gain Loss On Foreign Currency Derivative Instruments Not Designated As Hedging Instruments GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	-11000000	USD
CY2018	us-gaap	Gain Loss On Foreign Currency Derivative Instruments Not Designated As Hedging Instruments GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	-52000000	USD
CY2017	us-gaap	Gain Loss On Foreign Currency Derivative Instruments Not Designated As Hedging Instruments GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	133000000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	92000000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	28000000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	1403000000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	588000000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	3753000000	USD
CY2018	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	211000000	USD
CY2018	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	211000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1131000000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1110000000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	839000000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	790000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	292000000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	320000000	USD
CY2019	us-gaap	Depreciation Nonproduction DepreciationNonproduction	97000000	USD
CY2018	us-gaap	Depreciation Nonproduction DepreciationNonproduction	90000000	USD
CY2017	us-gaap	Depreciation Nonproduction DepreciationNonproduction	97000000	USD
CY2018Q4	us-gaap	Goodwill Gross GoodwillGross	3793000000	USD
CY2018Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	12000000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	3781000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	114000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	114000000	USD
CY2019	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-10000000	USD
CY2019	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-10000000	USD
CY2019	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	163000000	USD
CY2019	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	163000000	USD
CY2019Q4	us-gaap	Goodwill Gross GoodwillGross	3734000000	USD
CY2019Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	12000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	3722000000	USD
CY2017Q4	us-gaap	Goodwill Gross GoodwillGross	3765000000	USD
CY2017Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	12000000	USD
CY2018	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-183000000	USD
CY2018	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-183000000	USD
CY2018Q4	us-gaap	Goodwill Gross GoodwillGross	3793000000	USD
CY2018Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	12000000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	3781000000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	1498000000	USD
CY2018Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	1566000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	103000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	102000000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	61000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	99000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	99000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	99000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	96000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	94000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	1011000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	1498000000	USD
CY2017Q4	us-gaap	Restructuring Reserve RestructuringReserve	0	USD
CY2018Q4	us-gaap	Restructuring Reserve RestructuringReserve	42000000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	24000000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	24000000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	92000000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	3000000	USD
CY2019Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	95000000	USD
CY2018Q4	us-gaap	Derivative Assets DerivativeAssets	28000000	USD
CY2018Q4	us-gaap	Money Market Funds At Carrying Value MoneyMarketFundsAtCarryingValue	15000000	USD
CY2018Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	33000000	USD
CY2018Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	76000000	USD
CY2018Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	16000000	USD
CY2018Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	16000000	USD
CY2019Q4	us-gaap	Prepaid Taxes PrepaidTaxes	79000000	USD
CY2018Q4	us-gaap	Prepaid Taxes PrepaidTaxes	100000000	USD
CY2019Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	71000000	USD
CY2018Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	67000000	USD
CY2019Q4	us-gaap	Capitalized Contract Cost Net Current CapitalizedContractCostNetCurrent	91000000	USD
CY2018Q4	us-gaap	Capitalized Contract Cost Net Current CapitalizedContractCostNetCurrent	77000000	USD
CY2019Q4	us-gaap	Other Assets Miscellaneous Current OtherAssetsMiscellaneousCurrent	89000000	USD
CY2018Q4	us-gaap	Other Assets Miscellaneous Current OtherAssetsMiscellaneousCurrent	38000000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	330000000	USD
CY2018Q4	us-gaap	Other Assets Current OtherAssetsCurrent	282000000	USD
CY2019Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	117000000	USD
CY2018Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	105000000	USD
CY2019Q4	us-gaap	Deposit Assets DepositAssets	13000000	USD
CY2018Q4	us-gaap	Deposit Assets DepositAssets	14000000	USD
CY2019Q4	us-gaap	Business Combination Indemnification Assets Amount As Of Acquisition Date BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate	16000000	USD
CY2018Q4	us-gaap	Business Combination Indemnification Assets Amount As Of Acquisition Date BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate	16000000	USD
CY2019Q4	us-gaap	Long Term Investments LongTermInvestments	10000000	USD
CY2018Q4	us-gaap	Long Term Investments LongTermInvestments	18000000	USD
CY2019Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	119000000	USD
CY2018Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	79000000	USD
CY2019Q4	us-gaap	Interest Rate Derivative Assets At Fair Value InterestRateDerivativeAssetsAtFairValue	83000000	USD
CY2018Q4	us-gaap	Interest Rate Derivative Assets At Fair Value InterestRateDerivativeAssetsAtFairValue	27000000	USD
CY2019Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	31000000	USD
CY2018Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	16000000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	389000000	USD
CY2018Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	275000000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	152000000	USD
CY2018Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	113000000	USD
CY2019Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	208000000	USD
CY2018Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	155000000	USD
CY2019Q4	mco	Customer Billings And Payments Received In Advance CustomerBillingsAndPaymentsReceivedInAdvance	28000000	USD
CY2018Q4	mco	Customer Billings And Payments Received In Advance CustomerBillingsAndPaymentsReceivedInAdvance	20000000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	7000000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	7000000	USD
CY2019Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	43000000	USD
CY2018Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	48000000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	63000000	USD
CY2018Q4	us-gaap	Interest Payable Current InterestPayableCurrent	71000000	USD
CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	38000000	USD
CY2018Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	30000000	USD
CY2019Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	73000000	USD
CY2018Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	71000000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	7000000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	6000000	USD
CY2019Q4	us-gaap	Accrued Royalties Current AccruedRoyaltiesCurrent	25000000	USD
CY2018Q4	us-gaap	Accrued Royalties Current AccruedRoyaltiesCurrent	25000000	USD
CY2019Q4	us-gaap	Foreign Currency Contracts Liability Fair Value Disclosure ForeignCurrencyContractsLiabilityFairValueDisclosure	0	USD
CY2018Q4	us-gaap	Foreign Currency Contracts Liability Fair Value Disclosure ForeignCurrencyContractsLiabilityFairValueDisclosure	8000000	USD
CY2019Q4	us-gaap	Restructuring Reserve Current RestructuringReserveCurrent	21000000	USD
CY2018Q4	us-gaap	Restructuring Reserve Current RestructuringReserveCurrent	35000000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	108000000	USD
CY2018Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	107000000	USD
CY2019Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	773000000	USD
CY2018Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	696000000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	299000000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	249000000	USD
CY2019Q4	us-gaap	Deferred Rent Credit Noncurrent DeferredRentCreditNoncurrent	0	USD
CY2018Q4	us-gaap	Deferred Rent Credit Noncurrent DeferredRentCreditNoncurrent	94000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	82000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	70000000	USD
CY2019Q4	mco	Disposal Group Including Discontinued Operation Indemnification Provision Liability DisposalGroupIncludingDiscontinuedOperationIndemnificationProvisionLiability	43000000	USD
CY2018Q4	mco	Disposal Group Including Discontinued Operation Indemnification Provision Liability DisposalGroupIncludingDiscontinuedOperationIndemnificationProvisionLiability	0	USD
CY2019Q4	us-gaap	Income Tax Examination Liability Refund Adjustment From Settlement With Taxing Authority IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority	51000000	USD
CY2018Q4	us-gaap	Income Tax Examination Liability Refund Adjustment From Settlement With Taxing Authority IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority	125000000	USD
CY2019Q4	us-gaap	Interest Rate Derivative Liabilities At Fair Value InterestRateDerivativeLiabilitiesAtFairValue	0	USD
CY2018Q4	us-gaap	Interest Rate Derivative Liabilities At Fair Value InterestRateDerivativeLiabilitiesAtFairValue	8000000	USD
CY2019Q4	us-gaap	Restructuring Reserve Noncurrent RestructuringReserveNoncurrent	3000000	USD
CY2018Q4	us-gaap	Restructuring Reserve Noncurrent RestructuringReserveNoncurrent	7000000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	26000000	USD
CY2018Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	23000000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	504000000	USD
CY2018Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	576000000	USD
CY2019	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-25000000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-32000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-13000000	USD
CY2018	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-256000000	USD
CY2018	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-4000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-254000000	USD
CY2017	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	196000000	USD
CY2017	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	4000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	192000000	USD
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	45.73
CY2019	us-gaap	Employee Stock Ownership Plan Esop Dividends Paid To Esop EmployeeStockOwnershipPlanESOPDividendsPaidToESOP	1000000	USD
CY2017	us-gaap	Employee Stock Ownership Plan Esop Dividends Paid To Esop EmployeeStockOwnershipPlanESOPDividendsPaidToESOP	1000000	USD
CY2018	us-gaap	Employee Stock Ownership Plan Esop Dividends Paid To Esop EmployeeStockOwnershipPlanESOPDividendsPaidToESOP	1000000	USD
CY2019Q4	us-gaap	Employee Stock Ownership Plan Esop Shares In Esop EmployeeStockOwnershipPlanESOPSharesInESOP	411100	shares
CY2018Q4	us-gaap	Employee Stock Ownership Plan Esop Shares In Esop EmployeeStockOwnershipPlanESOPSharesInESOP	435500	shares
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	136000000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	130000000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	123000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	29000000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	43.29
CY2017	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y6M
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	32000000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	13000000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0114
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0105
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0134
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.24
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.26
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.27
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0256
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0282
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0219
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y2M12D
CY2018	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y2M12D
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	30.00
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2200000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	69.86
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	200000	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	175.30
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	800000	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	44.59
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	1600000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	93.51
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P5Y2M12D
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	227000000	USD
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	1500000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice	92.14
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1	P5Y1M6D
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	224000000	USD
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1100000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	71.64
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y
CY2019Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	176000000	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	36000000	USD
CY2018	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	38000000	USD
CY2017	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	49000000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	114000000	USD
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	99000000	USD
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	88000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	27000000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	24000000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	31000000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	179000000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	168000000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	454000000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	59000000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	50000000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	30000000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	181000000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	233000000	USD
CY2017	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	207000000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	419000000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	451000000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	691000000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-19000000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-59000000	USD
CY2017	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	156000000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-3000000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-2000000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	17000000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-16000000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-38000000	USD
CY2017	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-85000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-38000000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-99000000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	88000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	381000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	352000000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	779000000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.022
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.022
CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.019
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.001
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.018
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.099
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent	-0.028
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017Percent	0.170
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.021
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.011
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.004
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.210
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.211
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.436
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	458000000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	442000000	USD
CY2017	us-gaap	Income Taxes Paid IncomeTaxesPaid	366000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	1039000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	936000000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	1099000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	771000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	736000000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	688000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1810000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	37000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1672000000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1787000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	6000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	6000000	USD
CY2019Q4	mco	Deferred Tax Assets Accumulated Depreciation And Amortization Non Current DeferredTaxAssetsAccumulatedDepreciationAndAmortizationNonCurrent	1000000	USD
CY2018Q4	mco	Deferred Tax Assets Accumulated Depreciation And Amortization Non Current DeferredTaxAssetsAccumulatedDepreciationAndAmortizationNonCurrent	1000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	46000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	46000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	89000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	75000000	USD
CY2019Q4	mco	Deferred Tax Assets Operating Lease Liabilities DeferredTaxAssetsOperatingLeaseLiabilities	136000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Deferred Rent DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent	22000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	41000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Foreign DeferredTaxAssetsOperatingLossCarryforwardsForeign	13000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Foreign DeferredTaxAssetsOperatingLossCarryforwardsForeign	16000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Restructuring Charges DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringCharges	4000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Restructuring Charges DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringCharges	5000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	94000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	81000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Self Insurance DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance	8000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Self Insurance DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance	8000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	13000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	14000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	447000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	315000000	USD
CY2019Q4	mco	Deferred Tax Liabilities Accumulated Depreciation And Amortization Non Current DeferredTaxLiabilitiesAccumulatedDepreciationAndAmortizationNonCurrent	389000000	USD
CY2018Q4	mco	Deferred Tax Liabilities Accumulated Depreciation And Amortization Non Current DeferredTaxLiabilitiesAccumulatedDepreciationAndAmortizationNonCurrent	395000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	107000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	0	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	24000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	23000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Reserves And Accruals DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals	8000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Reserves And Accruals DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals	8000000	USD
CY2019Q4	us-gaap	Deferred Compensation Sharebased Arrangements Liability Current And Noncurrent DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent	2000000	USD
CY2018Q4	us-gaap	Deferred Compensation Sharebased Arrangements Liability Current And Noncurrent DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent	2000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	12000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	19000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	22000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	10000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	3000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	7000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	566000000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	465000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	119000000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	150000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	5000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	128000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	155000000	USD
CY2017Q4	us-gaap	Tax Cuts And Jobs Act Of2017 Incomplete Accounting Transition Tax For Accumulated Foreign Earnings Provisional Income Tax Expense TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense	247000000	USD
CY2018Q3	us-gaap	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense	236000000	USD
	us-gaap	Tax Cuts And Jobs Act Of2017 Measurement Period Adjustment Income Tax Expense Benefit TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit	-11000000	USD
CY2018	mco	Estimated Repatriation Tax Liability Resulting From The Tax Act Pay Period EstimatedRepatriationTaxLiabilityResultingFromTheTaxActPayPeriod	P8Y
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-44000000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.0242
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-38000000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.0223
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	5000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	477000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	422000000	USD
CY2018Q4	mco	Deferred Tax Asset For Potential Transition Tax Benefit If Foreign Unrecognized Tax Benefits Not Sustained DeferredTaxAssetForPotentialTransitionTaxBenefitIfForeignUnrecognizedTaxBenefitsNotSustained	48000000	USD
CY2019Q4	mco	Deferred Tax Asset For Potential Transition Tax Benefit If Foreign Unrecognized Tax Benefits Not Sustained DeferredTaxAssetForPotentialTransitionTaxBenefitIfForeignUnrecognizedTaxBenefitsNotSustained	50000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	495000000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	389000000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	200000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	35000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	80000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	86000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	22000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	89000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	120000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	2000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	13000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	4000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	1000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	2000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	2000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	44000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	48000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	11000000	USD
CY2019	mco	Unrecognized Tax Benefits Decrease Resulting From Divestiture UnrecognizedTaxBenefitsDecreaseResultingFromDivestiture	28000000	USD
CY2018	mco	Unrecognized Tax Benefits Decrease Resulting From Divestiture UnrecognizedTaxBenefitsDecreaseResultingFromDivestiture	0	USD
CY2017	mco	Unrecognized Tax Benefits Decrease Resulting From Divestiture UnrecognizedTaxBenefitsDecreaseResultingFromDivestiture	0	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	477000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	495000000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	389000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Expense UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense	28000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Expense UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense	15000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	82000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	70000000	USD
CY2019Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	5603000000	USD
CY2019Q4	us-gaap	Interest Rate Derivatives At Fair Value Net InterestRateDerivativesAtFairValueNet	-27000000	USD
CY2019	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	22000000	USD
CY2019Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	17000000	USD
CY2019Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	32000000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	5581000000	USD
CY2018Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	5722000000	USD
CY2018Q4	us-gaap	Interest Rate Derivatives At Fair Value Net InterestRateDerivativesAtFairValueNet	-2000000	USD
CY2018Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	18000000	USD
CY2018Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	30000000	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	5676000000	USD
CY2018Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	450000000	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5226000000	USD
CY2019	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	12000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	0	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	800000000	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	500000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	500000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	3303000000	USD
CY2019Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	5603000000	USD
CY2019	us-gaap	Investment Income Interest InvestmentIncomeInterest	17000000	USD
CY2018	us-gaap	Investment Income Interest InvestmentIncomeInterest	15000000	USD
CY2017	us-gaap	Investment Income Interest InvestmentIncomeInterest	16000000	USD
CY2019	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	176000000	USD
CY2018	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	197000000	USD
CY2017	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	190000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	28000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	15000000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	16000000	USD
CY2018	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	19000000	USD
CY2017	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	20000000	USD
CY2019	us-gaap	Interest Costs Capitalized Adjustment InterestCostsCapitalizedAdjustment	1000000	USD
CY2018	us-gaap	Interest Costs Capitalized Adjustment InterestCostsCapitalizedAdjustment	1000000	USD
CY2017	us-gaap	Interest Costs Capitalized Adjustment InterestCostsCapitalizedAdjustment	1000000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-208000000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-215000000	USD
CY2017	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-209000000	USD
CY2019	us-gaap	Interest Paid InterestPaid	167000000	USD
CY2018	us-gaap	Interest Paid InterestPaid	183000000	USD
CY2017	us-gaap	Interest Paid InterestPaid	158000000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	5581000000	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	5676000000	USD
CY2019Q4	us-gaap	Capital Units Authorized CapitalUnitsAuthorized	1020000000.00	shares
CY2019Q4	mco	Shares Of All Classes Of Stock Par Value SharesOfAllClassesOfStockParValue	0.01
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000.0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000.0	shares
CY2019	us-gaap	Schedule Of Repurchase Agreements ScheduleOfRepurchaseAgreements	The table below summarizes the Company’s remaining authority under its share repurchase program as of December 31, 2019:<table style="margin-left:auto;margin-right:auto;border-collapse:collapse;text-align:left;text-indent:0pt;display:inline-table;width:99.707%;"><tr><td style="width:1.0%;"/><td style="width:61.343%;"/><td style="width:1.0%;"/><td style="width:0.1%;"/><td style="width:0.533%;"/><td style="width:0.1%;"/><td style="width:1.0%;"/><td style="width:15.595%;"/><td style="width:1.0%;"/><td style="width:0.1%;"/><td style="width:0.533%;"/><td style="width:0.1%;"/><td style="width:1.0%;"/><td style="width:15.596%;"/><td style="width:1.0%;"/></tr><tr><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:rgb(255,255,255, 0.0);text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"><span style="font-size:8pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">Date Authorized</span></td><td colspan="3" style="background-color:rgb(255,255,255, 0.0);text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:rgb(255,255,255, 0.0);text-align:right;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"><span style="font-size:8pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">Amount Authorized</span></td><td colspan="3" style="background-color:rgb(255,255,255, 0.0);text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:rgb(255,255,255, 0.0);text-align:right;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"><span style="font-size:8pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">Remaining Authority</span></td></tr><tr><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:left;vertical-align:top;border-top:1pt solid #000000;padding-left:1pt;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">October 22, 2018</span></td><td colspan="3" style="background-color:#cceeff;text-align:left;vertical-align:top;padding-left:1pt;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"/></span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:left;vertical-align:bottom;border-top:1pt solid #000000;padding-left:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">$</span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000000;padding-right:0%;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">1,000 </span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000000;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"> </span></td><td colspan="3" style="background-color:#cceeff;text-align:right;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"/></span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:left;vertical-align:bottom;border-top:1pt solid #000000;padding-left:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">$</span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000000;padding-right:0%;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">334 </span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000000;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"> </span></td></tr><tr><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:left;vertical-align:top;padding-left:1pt;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">December 16, 2019</span></td><td colspan="3" style="background-color:#ffffff;text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:left;vertical-align:bottom;padding-left:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">$</span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:right;vertical-align:bottom;padding-right:0%;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">1,000 </span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:right;vertical-align:bottom;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"> </span></td><td colspan="3" style="background-color:#ffffff;text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td colspan="2" style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:right;vertical-align:bottom;padding-left:1pt;padding-right:0%;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">1,000 </span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#ffffff;text-align:right;vertical-align:bottom;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"> </span></td></tr><tr><td colspan="3" style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:left;vertical-align:top;padding-left:1pt;padding-right:1pt;"><span style="font-size:9pt;font-weight:400;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">Total Remaining Authority</span></td><td colspan="3" style="background-color:#cceeff;text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td colspan="3" style="background-color:#cceeff;text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td colspan="3" style="background-color:#cceeff;text-align:left;vertical-align:bottom;padding-left:1pt;padding-right:1pt;"/><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:left;vertical-align:bottom;border-top:1pt solid #000;border-bottom:2pt solid #000000;padding-left:1pt;"><span style="font-size:9pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">$</span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000;border-bottom:2pt solid #000000;padding-right:0%;"><span style="font-size:9pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);">1,334 </span></td><td style="padding-top:2px;padding-bottom:2px;background-color:#cceeff;text-align:right;vertical-align:bottom;border-top:1pt solid #000;border-bottom:2pt solid #000000;padding-right:1pt;"><span style="font-size:9pt;font-weight:700;font-family:'Arial',sans-serif;color:#000000;background-color:rgb(255,255,255, 0.0);"> </span></td></tr></table>
CY2019Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	1334000000	USD
CY2019	us-gaap	Stock Issued During Period Shares Share Based Compensation Gross StockIssuedDuringPeriodSharesShareBasedCompensationGross	1600000	shares
CY2019Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2019Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.44
CY2018Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2017Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0
CY2017Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.38
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	97000000	USD
CY2019	us-gaap	Sublease Income SubleaseIncome	2000000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.00
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	2.00
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.76
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.76
CY2017	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.14
CY2017	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.52
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	17000000	USD
CY2019	us-gaap	Lease Cost LeaseCost	112000000	USD
CY2019Q2	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	25000000	USD
CY2019Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.44
CY2018Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2017Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.38
CY2017Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.38
CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2019Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.44
CY2018Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2017Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.38
CY2017Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.38
CY2019Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2019Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.44
CY2018Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2017Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.38
CY2017Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.38
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	106000000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	41000000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y9M18D
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.036
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	107000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	103000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	91000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	85000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	79000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	183000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	648000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	74000000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	574000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	89000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	485000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	106000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	102000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	96000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	84000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	81000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	247000000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	716000000	USD
CY2013Q3	us-gaap	Loss Contingency Damages Sought Value LossContingencyDamagesSoughtValue	120000000	USD
CY2013Q3	us-gaap	Litigation Settlement Amount Awarded To Other Party LitigationSettlementAmountAwardedToOtherParty	15500000	USD
CY2019	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	2	segment
CY2019	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2019	us-gaap	Operating Expenses OperatingExpenses	2831000000	USD
CY2018	us-gaap	Operating Expenses OperatingExpenses	2575000000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	1998000000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	1868000000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	60000000	USD
CY2018	us-gaap	Restructuring Charges RestructuringCharges	49000000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	200000000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	192000000	USD
CY2019	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	3000000	USD
CY2018	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	8000000	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-14000000	USD
CY2018	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Litigation Settlement Amount Awarded To Other Party LitigationSettlementAmountAwardedToOtherParty	16000000	USD
CY2018	us-gaap	Litigation Settlement Amount Awarded To Other Party LitigationSettlementAmountAwardedToOtherParty	0	USD
CY2019	mco	Adjusted Operating Income AdjustedOperatingIncome	2291000000	USD
CY2018	mco	Adjusted Operating Income AdjustedOperatingIncome	2117000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2017	us-gaap	Operating Expenses OperatingExpenses	2383000000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	1821000000	USD
CY2017	us-gaap	Depreciation And Amortization DepreciationAndAmortization	158000000	USD
CY2017	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	23000000	USD
CY2017	mco	Adjusted Operating Income AdjustedOperatingIncome	2002000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4829000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4443000000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	4204000000	USD
CY2019Q4	us-gaap	Noncurrent Assets NoncurrentAssets	5968000000	USD
CY2018Q4	us-gaap	Noncurrent Assets NoncurrentAssets	5667000000	USD
CY2017Q4	us-gaap	Noncurrent Assets NoncurrentAssets	5710000000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	43000000	USD
CY2019	us-gaap	Allowance For Doubtful Accounts Receivable Period Increase Decrease AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease	11000000	USD
CY2019	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	11000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	43000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	5000000	USD
CY2019	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	4000000	USD
CY2019	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9000000	USD
CY2017Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	37000000	USD
CY2018	us-gaap	Allowance For Doubtful Accounts Receivable Period Increase Decrease AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease	18000000	USD
CY2018	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	12000000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	43000000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	6000000	USD
CY2018	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	0	USD
CY2018	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	1000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	5000000	USD
CY2016Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	26000000	USD
CY2017	us-gaap	Allowance For Doubtful Accounts Receivable Period Increase Decrease AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease	20000000	USD
CY2017	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	9000000	USD
CY2017Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	37000000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	3000000	USD
CY2017	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	3000000	USD
CY2017	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	0	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	6000000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-18000000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-11000000	USD
CY2017	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-17000000	USD
CY2019	mco	Pension Expense Net Periodic Pension Costs Other PensionExpenseNetPeriodicPensionCostsOther	18000000	USD
CY2018	mco	Pension Expense Net Periodic Pension Costs Other PensionExpenseNetPeriodicPensionCostsOther	10000000	USD
CY2017	mco	Pension Expense Net Periodic Pension Costs Other PensionExpenseNetPeriodicPensionCostsOther	8000000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	13000000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	483000000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	14000000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	13000000	USD
CY2019	mco	Other Non Operating Income Expense Other OtherNonOperatingIncomeExpenseOther	7000000	USD
CY2018	mco	Other Non Operating Income Expense Other OtherNonOperatingIncomeExpenseOther	6000000	USD
CY2017	mco	Other Non Operating Income Expense Other OtherNonOperatingIncomeExpenseOther	0	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	20000000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	19000000	USD
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	4000000	USD
CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1142000000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1214000000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1240000000	USD
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1233000000	USD
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	462000000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	549000000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	504000000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	373000000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	310000000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	380000000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	359000000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.96
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.64
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.01
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.91
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.93
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.62
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.99
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.88
CY2018Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1127000000	USD
CY2018Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1175000000	USD
CY2018Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1081000000	USD
CY2018Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1060000000	USD
CY2018Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	491000000	USD
CY2018Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	534000000	USD
CY2018Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	467000000	USD
CY2018Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	376000000	USD
CY2018Q1	us-gaap	Net Income Loss NetIncomeLoss	373000000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	376000000	USD
CY2018Q3	us-gaap	Net Income Loss NetIncomeLoss	310000000	USD
CY2018Q4	us-gaap	Net Income Loss NetIncomeLoss	251000000	USD
CY2018Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.95
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.96
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.62
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.31
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.92
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.94
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.59
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.29
CY2018Q3	us-gaap	Tax Cuts And Jobs Act Of2017 Income Tax Expense Benefit TaxCutsAndJobsActOf2017IncomeTaxExpenseBenefit	-65000000	USD
CY2018Q4	us-gaap	Restructuring Charges RestructuringCharges	49000000	USD

Files In Submission

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$MCO
MOODYS CORP /DE/ Stock $mco

2019 Q4 Form 10-K Financial Statement

#000105955620000005 Filed on February 24, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MCO MOODYS CORP /DE/ Stock $mco

2019 Q4 Form 10-K Financial Statement

#000105955620000005 Filed on February 24, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MCO
MOODYS CORP /DE/ Stock $mco