$CB
Chubb Ltd Stock $cb

$cb Overview Financials Valuation SEC Filings Company Website

2019 Q4 Form 10-K Financial Statement

#000089615921000003 Filed on February 25, 2021

Income Statement

Concept	2019 Q4	2018 Q4	2018
Revenue	$8.738B	$7.626B	$32.72B
YoY Change	14.58%	-4.85%	1.47%
Cost Of Revenue	$4.865B	$4.610B	$18.07B
YoY Change	5.53%	7.91%	-2.1%
Gross Profit	$3.873B	$3.016B	$14.65B
YoY Change	28.42%	-19.42%	6.24%
Gross Profit Margin	44.32%	39.55%	44.78%
Selling, General & Admin	$816.0M	$726.0M	$2.898B
YoY Change	12.4%	-2.94%	1.05%
% of Gross Profit	21.07%	24.07%	19.78%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$76.00M	$86.00M	$5.912B
YoY Change	-11.63%	30.3%	2.27%
% of Gross Profit	1.96%	2.85%	40.35%
Operating Expenses	$7.524B	$7.064B	$27.81B
YoY Change	6.51%	4.51%	-1.01%
Operating Profit	-$3.651B	-$4.048B	-$13.16B
YoY Change	-9.81%	34.22%	-8.0%
Interest Expense	$130.0M	$7.000M	$641.0M
YoY Change	1757.14%	-117.5%	5.6%
% of Operating Profit
Other Income/Expense, Net	-$12.00M	-$15.00M	$434.0M
YoY Change	-20.0%	0.0%	8.5%
Pretax Income	$1.342B	$514.0M	$4.657B
YoY Change	161.09%	-55.34%	25.12%
Income Tax	$169.0M	$184.0M	$695.0M
% Of Pretax Income	12.59%	35.8%	14.92%
Net Earnings	$1.173B	$355.0M	$3.962B
YoY Change	230.42%	-76.84%	2.62%
Net Earnings / Revenue	13.42%	4.66%	12.11%
Basic Earnings Per Share	$2.59	$0.77	$8.55
Diluted Earnings Per Share	$2.57	$0.76	$8.49
COMMON SHARES
Basic Shares Outstanding	453.2M shares	460.8M shares	463.6M shares
Diluted Shares Outstanding			466.8M shares

Balance Sheet

Concept	2019 Q4	2018 Q4	2018
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$1.537B	$1.247B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$1.900B	$1.700B	$1.700B
YoY Change	11.76%	30.77%	30.77%
Goodwill	$15.30B	$15.27B
YoY Change	0.16%	-1.74%
Intangibles	$6.063B	$6.143B
YoY Change	-1.3%	-5.68%
Long-Term Investments	$110.6B	$101.6B	$101.6B
YoY Change	8.78%	-1.42%	-1.42%
Other Assets	$109.0M	$93.00M	$93.00M
YoY Change	17.2%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$176.9B	$167.8B	$167.8B
YoY Change	5.47%	0.45%	0.45%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$11.06B	$10.47B	$10.47B
YoY Change	5.65%	9.71%	9.71%
Accrued Expenses	$603.0M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$1.299B	$509.0M	$509.0M
YoY Change	155.21%	-49.75%	-49.75%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$19.15B	$17.42B	$17.42B
YoY Change	9.94%	6.04%	6.04%
LONG-TERM LIABILITIES
Long-Term Debt	$13.87B	$12.40B	$12.40B
YoY Change	11.88%	4.48%	4.48%
Other Long-Term Liabilities	$1.003B	$861.0M	$861.0M
YoY Change	16.49%	56.55%	56.55%
Total Long-Term Liabilities	$14.87B	$13.26B	$13.26B
YoY Change	12.18%	6.78%	6.78%
TOTAL LIABILITIES
Total Short-Term Liabilities	$19.15B	$17.42B	$17.42B
Total Long-Term Liabilities	$14.87B	$13.26B	$13.26B
Total Liabilities	$121.6B	$117.5B	$117.5B
YoY Change	3.54%	1.39%	1.39%
SHAREHOLDERS EQUITY
Retained Earnings	$36.14B	$31.70B
YoY Change	14.01%	15.38%
Common Stock	$22.32B	$23.68B
YoY Change	-5.72%	-5.66%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$3.754B	$2.618B
YoY Change	43.39%	34.67%
Treasury Stock Shares	27.81M shares	20.58M shares
Shareholders Equity	$55.33B	$50.31B	$50.31B
YoY Change
Total Liabilities & Shareholders Equity	$176.9B	$167.8B	$167.8B
YoY Change	5.47%	0.45%	0.45%

Cashflow Statement

Concept	2019 Q4	2018 Q4	2018
OPERATING ACTIVITIES
Net Income	$1.173B	$355.0M	$3.962B
YoY Change	230.42%	-76.84%	2.62%
Depreciation, Depletion And Amortization	$76.00M	$86.00M	$5.912B
YoY Change	-11.63%	30.3%	2.27%
Cash From Operating Activities	$1.429B	$1.583B	$5.480B
YoY Change	-9.73%	44.96%	21.7%
INVESTING ACTIVITIES
Capital Expenditures
YoY Change
Acquisitions			$0.00
YoY Change
Other Investing Activities	-$2.344B	-$808.0M	$533.0M
YoY Change	190.1%	-25.25%	0.57%
Cash From Investing Activities	-$2.344B	-$808.0M	-$2.935B
YoY Change	190.1%	-25.25%	21.18%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$1.044B
YoY Change			30.34%
Debt Paid & Issued, Net			$2.001B
YoY Change			299.4%
Cash From Financing Activities	973.0M	-567.0M	-$1.991B
YoY Change	-271.6%	62.46%	-14.14%
NET CHANGE
Cash From Operating Activities	1.429B	1.583B	$5.480B
Cash From Investing Activities	-2.344B	-808.0M	-$2.935B
Cash From Financing Activities	973.0M	-567.0M	-$1.991B
Net Change In Cash	58.00M	208.0M	$489.0M
YoY Change	-72.12%	-161.54%	-306.33%
FREE CASH FLOW
Cash From Operating Activities	$1.429B	$1.583B	$5.480B
Capital Expenditures
Free Cash Flow
YoY Change

Facts In Submission

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CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	596000000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	434000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	290000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	305000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	339000000	USD
CY2020	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	0	USD
CY2019	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	23000000	USD
CY2018	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	59000000	USD
CY2020	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	31832000000	USD
CY2019	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	28937000000	USD
CY2018	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	28060000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	4162000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	5249000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	4657000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	629000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	795000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	695000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3533000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	4454000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	3962000000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	2311000000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	3704000000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-2298000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-281000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-31000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-302000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	2592000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	3735000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	-1996000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	306000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	13000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-802000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	232000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	76000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	321000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	2666000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	3672000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-3119000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	416000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	605000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-399000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	2250000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	3067000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-2720000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	5783000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	7521000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1242000000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.82
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	9.77
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	8.55
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.79
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	9.71
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	8.49
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	426000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	647000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax	-338000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-36000000	USD
CY2019	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 Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-41000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	462000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	647000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-297000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	24000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	35000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	50000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	18000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	67000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	59441000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	55331000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	50312000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3533000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	4454000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	3962000000	USD
CY2020	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-498000000	USD
CY2019	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-530000000	USD
CY2018	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-652000000	USD
CY2020	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	367000000	USD
CY2019	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	395000000	USD
CY2018	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	592000000	USD
CY2020	us-gaap	Present Value Of Future Insurance Profits Amortization Expense1 PresentValueOfFutureInsuranceProfitsAmortizationExpense1	290000000	USD
CY2019	us-gaap	Present Value Of Future Insurance Profits Amortization Expense1 PresentValueOfFutureInsuranceProfitsAmortizationExpense1	305000000	USD
CY2018	us-gaap	Present Value Of Future Insurance Profits Amortization Expense1 PresentValueOfFutureInsuranceProfitsAmortizationExpense1	339000000	USD
CY2020	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	333000000	USD
CY2019	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	97000000	USD
CY2018	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-16000000	USD
CY2020	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	4664000000	USD
CY2019	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	-257000000	USD
CY2018	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	570000000	USD
CY2020	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	846000000	USD
CY2019	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	1051000000	USD
CY2018	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	654000000	USD
CY2020	us-gaap	Increase Decrease In Future Policy Benefit Reserves IncreaseDecreaseInFuturePolicyBenefitReserves	236000000	USD
CY2019	us-gaap	Increase Decrease In Future Policy Benefit Reserves IncreaseDecreaseInFuturePolicyBenefitReserves	215000000	USD
CY2018	us-gaap	Increase Decrease In Future Policy Benefit Reserves IncreaseDecreaseInFuturePolicyBenefitReserves	235000000	USD
CY2020	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	535000000	USD
CY2019	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	-302000000	USD
CY2018	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	722000000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-98000000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-207000000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	375000000	USD
CY2020	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	46000000	USD
CY2019	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-7000000	USD
CY2018	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	161000000	USD
CY2020	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	114000000	USD
CY2019	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	270000000	USD
CY2018	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	981000000	USD
CY2020	cb	Increase Decrease In Reinsurance Recoverable Losses And Loss Expenses IncreaseDecreaseInReinsuranceRecoverableLossesAndLossExpenses	-336000000	USD
CY2019	cb	Increase Decrease In Reinsurance Recoverable Losses And Loss Expenses IncreaseDecreaseInReinsuranceRecoverableLossesAndLossExpenses	838000000	USD
CY2018	cb	Increase Decrease In Reinsurance Recoverable Losses And Loss Expenses IncreaseDecreaseInReinsuranceRecoverableLossesAndLossExpenses	-1165000000	USD
CY2020	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	89000000	USD
CY2019	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	344000000	USD
CY2018	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	301000000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	260000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-38000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	351000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	9785000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	6342000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	5480000000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	26298000000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	25846000000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	24700000000	USD
CY2020	cb	Payments To Acquire To Be Announced Mortgage Backed Securities PaymentsToAcquireToBeAnnouncedMortgageBackedSecurities	0	USD
CY2019	cb	Payments To Acquire To Be Announced Mortgage Backed Securities PaymentsToAcquireToBeAnnouncedMortgageBackedSecurities	0	USD
CY2018	cb	Payments To Acquire To Be Announced Mortgage Backed Securities PaymentsToAcquireToBeAnnouncedMortgageBackedSecurities	35000000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	202000000	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	229000000	USD
CY2018	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	456000000	USD
CY2018	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	6419000000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	531000000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	207000000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	11377000000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	13110000000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	14001000000	USD
CY2020	cb	Proceeds From Sales To Be Announced Mortgage Backed Securities ProceedsFromSalesToBeAnnouncedMortgageBackedSecurities	0	USD
CY2019	cb	Proceeds From Sales To Be Announced Mortgage Backed Securities ProceedsFromSalesToBeAnnouncedMortgageBackedSecurities	6000000	USD
CY2018	cb	Proceeds From Sales To Be Announced Mortgage Backed Securities ProceedsFromSalesToBeAnnouncedMortgageBackedSecurities	29000000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	3880000000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	611000000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	315000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	12450000000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	9039000000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	7352000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	995000000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	946000000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	1124000000	USD
CY2020	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	81000000	USD
CY2019	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	1117000000	USD
CY2018	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	-516000000	USD
CY2020	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	113000000	USD
CY2019	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	703000000	USD
CY2018	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	-16000000	USD
CY2020	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1924000000	USD
CY2019	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1315000000	USD
CY2018	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1337000000	USD
CY2020	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	907000000	USD
CY2019	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	1390000000	USD
CY2018	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	980000000	USD
CY2020	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2019	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	45000000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	29000000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	470000000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	657000000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	533000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-7521000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-5905000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2935000000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	1388000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	1354000000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	1337000000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	523000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1530000000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1044000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	988000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	2828000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	2171000000	USD
CY2020	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	2354000000	USD
CY2019	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	2817000000	USD
CY2018	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	2029000000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1301000000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	510000000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	2001000000	USD
CY2020	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	2354000000	USD
CY2019	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	2817000000	USD
CY2018	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	2019000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	145000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	204000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	115000000	USD
CY2020	us-gaap	Additions To Contract Holders Funds AdditionsToContractHoldersFunds	470000000	USD
CY2019	us-gaap	Additions To Contract Holders Funds AdditionsToContractHoldersFunds	514000000	USD
CY2018	us-gaap	Additions To Contract Holders Funds AdditionsToContractHoldersFunds	453000000	USD
CY2020	us-gaap	Withdrawal From Contract Holders Funds WithdrawalFromContractHoldersFunds	386000000	USD
CY2019	us-gaap	Withdrawal From Contract Holders Funds WithdrawalFromContractHoldersFunds	303000000	USD
CY2018	us-gaap	Withdrawal From Contract Holders Funds WithdrawalFromContractHoldersFunds	358000000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-87000000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-2082000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-151000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-1991000000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	8000000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	20000000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-65000000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	190000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	306000000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	489000000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	621000000	USD
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CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	90699000000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	27720000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	27232000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	27232000000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	24874000000	USD
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CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	14010000000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	8874000000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	19192000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	90699000000	USD
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CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	82580000000	USD
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CY2020	cb	Debt Securities Available For Sale Credit Impairment Charges Intent To Sell DebtSecuritiesAvailableForSaleCreditImpairmentChargesIntentToSell	-170000000	USD
CY2019	cb	Debt Securities Available For Sale Credit Impairment Charges Intent To Sell DebtSecuritiesAvailableForSaleCreditImpairmentChargesIntentToSell	0	USD
CY2018	cb	Debt Securities Available For Sale Credit Impairment Charges Intent To Sell DebtSecuritiesAvailableForSaleCreditImpairmentChargesIntentToSell	0	USD
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CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	89000000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	109000000	USD
CY2020Q4	us-gaap	Funds Held Under Reinsurance Agreements Asset FundsHeldUnderReinsuranceAgreementsAsset	12305000000	USD
CY2019Q4	us-gaap	Funds Held Under Reinsurance Agreements Asset FundsHeldUnderReinsuranceAgreementsAsset	14004000000	USD
CY2020Q4	cb	Restricted Assets Deposits With United States Regulatory Authorities RestrictedAssetsDepositsWithUnitedStatesRegulatoryAuthorities	2438000000	USD
CY2019Q4	cb	Restricted Assets Deposits With United States Regulatory Authorities RestrictedAssetsDepositsWithUnitedStatesRegulatoryAuthorities	2466000000	USD
CY2020Q4	cb	Restricted Assets Deposits With Non United States Regulatory Authorities RestrictedAssetsDepositsWithNonUnitedStatesRegulatoryAuthorities	2905000000	USD
CY2019Q4	cb	Restricted Assets Deposits With Non United States Regulatory Authorities RestrictedAssetsDepositsWithNonUnitedStatesRegulatoryAuthorities	2709000000	USD
CY2020Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities For Repurchase Agreements PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForRepurchaseAgreements	1462000000	USD
CY2019Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities For Repurchase Agreements PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForRepurchaseAgreements	1464000000	USD
CY2020Q4	cb	Restricted Assets Other Pledged Assets RestrictedAssetsOtherPledgedAssets	584000000	USD
CY2019Q4	cb	Restricted Assets Other Pledged Assets RestrictedAssetsOtherPledgedAssets	490000000	USD
CY2020Q4	us-gaap	Restricted Cash And Investments RestrictedCashAndInvestments	19694000000	USD
CY2019Q4	us-gaap	Restricted Cash And Investments RestrictedCashAndInvestments	21133000000	USD
CY2019	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	3276000000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	30064000000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	12510000000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	13005000000	USD
CY2020	us-gaap	Direct Premiums Written DirectPremiumsWritten	37749000000	USD
CY2019	us-gaap	Direct Premiums Written DirectPremiumsWritten	36848000000	USD
CY2018	us-gaap	Direct Premiums Written DirectPremiumsWritten	34782000000	USD
CY2020	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	3512000000	USD
CY2018	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	3186000000	USD
CY2020	us-gaap	Ceded Premiums Written CededPremiumsWritten	7441000000	USD
CY2019	us-gaap	Ceded Premiums Written CededPremiumsWritten	7849000000	USD
CY2018	us-gaap	Ceded Premiums Written CededPremiumsWritten	7389000000	USD
CY2020	us-gaap	Premiums Written Net PremiumsWrittenNet	33820000000	USD
CY2019	us-gaap	Premiums Written Net PremiumsWrittenNet	32275000000	USD
CY2018	us-gaap	Premiums Written Net PremiumsWrittenNet	30579000000	USD
CY2020	us-gaap	Direct Premiums Earned DirectPremiumsEarned	37037000000	USD
CY2019	us-gaap	Direct Premiums Earned DirectPremiumsEarned	35876000000	USD
CY2018	us-gaap	Direct Premiums Earned DirectPremiumsEarned	34108000000	USD
CY2020	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	3323000000	USD
CY2019	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	3107000000	USD
CY2018	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	3175000000	USD
CY2020	us-gaap	Ceded Premiums Earned CededPremiumsEarned	7243000000	USD
CY2019	us-gaap	Ceded Premiums Earned CededPremiumsEarned	7693000000	USD
CY2018	us-gaap	Ceded Premiums Earned CededPremiumsEarned	7219000000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	33117000000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	31290000000	USD
CY2020	cb	Reinsurance Recoveries Losses And Loss Expenses Incurred ReinsuranceRecoveriesLossesAndLossExpensesIncurred	5000000000.0	USD
CY2019	cb	Reinsurance Recoveries Losses And Loss Expenses Incurred ReinsuranceRecoveriesLossesAndLossExpensesIncurred	4900000000	USD
CY2018	cb	Reinsurance Recoveries Losses And Loss Expenses Incurred ReinsuranceRecoveriesLossesAndLossExpensesIncurred	5600000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	14647000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables On Unpaid Losses Allowance ReinsuranceRecoverablesOnUnpaidLossesAllowance	257000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	14181000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables On Unpaid Losses Allowance ReinsuranceRecoverablesOnUnpaidLossesAllowance	240000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables On Paid Losses ReinsuranceRecoverablesOnPaidLosses	945000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables On Paid Losses Allowance ReinsuranceRecoverablesOnPaidLossesAllowance	57000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables On Paid Losses ReinsuranceRecoverablesOnPaidLosses	1000000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables On Paid Losses Allowance ReinsuranceRecoverablesOnPaidLossesAllowance	76000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	15592000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	314000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	15181000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	316000000	USD
CY2020Q4	cb	Reinsurance Recoverable Future Policy Benefits ReinsuranceRecoverableFuturePolicyBenefits	206000000	USD
CY2020Q4	cb	Reinsurance Recoverableson Future Policy Benefits Allowance ReinsuranceRecoverablesonFuturePolicyBenefitsAllowance	5000000	USD
CY2019Q4	cb	Reinsurance Recoverable Future Policy Benefits ReinsuranceRecoverableFuturePolicyBenefits	197000000	USD
CY2019Q4	cb	Reinsurance Recoverableson Future Policy Benefits Allowance ReinsuranceRecoverablesonFuturePolicyBenefitsAllowance	4000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	316000000	USD
CY2020	us-gaap	Reinsurance Recoverable Credit Loss Expense Reversal ReinsuranceRecoverableCreditLossExpenseReversal	21000000	USD
CY2020	us-gaap	Reinsurance Loss On Uncollectible Accounts In Period Amount ReinsuranceLossOnUncollectibleAccountsInPeriodAmount	25000000	USD
CY2020	cb	Reinsurance Recoverable Allowance For Credit Loss Other ReinsuranceRecoverableAllowanceForCreditLossOther	2000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	314000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	15906000000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	314000000	USD
CY2020Q4	cb	Allowance For Reinsurance Recoverable Percentage AllowanceForReinsuranceRecoverablePercentage	0.020
CY2018Q4	us-gaap	Goodwill Goodwill	15271000000	USD
CY2019	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	25000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	15296000000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	60000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	15400000000	USD
CY2020Q4	us-gaap	Other Intangible Assets Net OtherIntangibleAssetsNet	5811000000	USD
CY2019Q4	us-gaap	Other Intangible Assets Net OtherIntangibleAssetsNet	6063000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	2846000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	3114000000	USD
CY2020Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	2965000000	USD
CY2019Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	2949000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	290000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	305000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	339000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	286000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	284000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	267000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	244000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	228000000	USD
CY2020Q4	cb	Finitelivedintangibleassetsamortizationexpensetotal Finitelivedintangibleassetsamortizationexpensetotal	1309000000	USD
CY2019Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	306000000	USD
CY2018Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	295000000	USD
CY2017Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	326000000	USD
CY2020	us-gaap	Amortization Of Value Of Business Acquired Voba AmortizationOfValueOfBusinessAcquiredVOBA	27000000	USD
CY2019	us-gaap	Amortization Of Value Of Business Acquired Voba AmortizationOfValueOfBusinessAcquiredVOBA	24000000	USD
CY2018	us-gaap	Amortization Of Value Of Business Acquired Voba AmortizationOfValueOfBusinessAcquiredVOBA	25000000	USD
CY2020	cb	Intangible Assets Arising From Insurance Contracts Acquired In Business Combination Foreign Exchange Revaluation IntangibleAssetsArisingFromInsuranceContractsAcquiredInBusinessCombinationForeignExchangeRevaluation	-16000000	USD
CY2019	cb	Intangible Assets Arising From Insurance Contracts Acquired In Business Combination Foreign Exchange Revaluation IntangibleAssetsArisingFromInsuranceContractsAcquiredInBusinessCombinationForeignExchangeRevaluation	35000000	USD
CY2018	cb	Intangible Assets Arising From Insurance Contracts Acquired In Business Combination Foreign Exchange Revaluation IntangibleAssetsArisingFromInsuranceContractsAcquiredInBusinessCombinationForeignExchangeRevaluation	-6000000	USD
CY2020Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	263000000	USD
CY2019Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	306000000	USD
CY2018Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	295000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Amortization Expense Year One PresentValueOfFutureInsuranceProfitsAmortizationExpenseYearOne	22000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Amortization Expense Year Two PresentValueOfFutureInsuranceProfitsAmortizationExpenseYearTwo	21000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Amortization Expense Year Three PresentValueOfFutureInsuranceProfitsAmortizationExpenseYearThree	19000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Amortization Expense Year Four PresentValueOfFutureInsuranceProfitsAmortizationExpenseYearFour	17000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Amortization Expense Year Five PresentValueOfFutureInsuranceProfitsAmortizationExpenseYearFive	16000000	USD
CY2020Q4	us-gaap	Present Value Of Future Insurance Profits Accumulated Amortization PresentValueOfFutureInsuranceProfitsAccumulatedAmortization	95000000	USD
CY2020	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-bottom:7pt"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:120%">Chubb establishes reserves for the estimated unpaid ultimate liability for losses and loss expenses under the terms of its policies and agreements. Reserves include estimates for both claims that have been reported and for IBNR claims, and include estimates of expenses associated with processing and settling these claims. Reserves are recorded in Unpaid losses and loss expenses in the consolidated balance sheets. While we believe that our reserves for unpaid losses and loss expenses at December 31, 2020 are adequate, new information or trends may lead to future developments in incurred loss and loss expenses significantly greater or less than the reserves provided. Any such revisions could result in future changes in estimates of losses or reinsurance recoverable and would be reflected in our results of operations in the period in which the estimates are changed.</span></div><div><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:120%">The following table presents a reconciliation of beginning and ending Unpaid losses and loss expenses:</span></div><div style="margin-bottom:5pt;margin-top:5pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;vertical-align:top;width:100.000%"><tr><td style="width:1.0%"/><td style="width:63.871%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:10.058%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.506%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:10.058%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.506%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:10.201%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="15" style="padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Year Ended December 31</span></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(in millions of U.S. dollars)</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">2020</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2019</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2018</span></td></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Gross unpaid losses and loss expenses, beginning of year</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">62,690</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">62,960 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">63,179 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Reinsurance recoverable on unpaid losses </span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:4.55pt;font-weight:400;line-height:100%;position:relative;top:-2.44pt;vertical-align:baseline">(1)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">(14,181)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(14,689)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(14,014)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Net unpaid losses and loss expenses, beginning of year</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">48,509</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">48,271 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">49,165 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/></tr><tr><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/></tr><tr><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Net losses and loss expenses incurred in respect of losses occurring in:</span></td><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Current year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">22,124</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">19,575 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">19,048 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Prior years </span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:4.55pt;font-weight:400;line-height:100%;position:relative;top:-2.44pt;vertical-align:baseline">(2)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">(414)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(845)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(981)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Total</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">21,710</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">18,730 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">18,067 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Net losses and loss expenses paid in respect of losses occurring in:</span></td><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Current year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">7,782</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">7,894 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">7,544 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Prior years</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">9,652</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,579 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,796 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Total</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">17,434</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">18,473 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">18,340 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Foreign currency revaluation and other</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">379</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(19)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(621)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Net unpaid losses and loss expenses, end of year</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">53,164</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">48,509 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">48,271 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Reinsurance recoverable on unpaid losses </span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:4.55pt;font-weight:400;line-height:100%;position:relative;top:-2.44pt;vertical-align:baseline">(1)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">14,647</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">14,181 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">14,689 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:9.75pt;font-weight:400;line-height:100%">Gross unpaid losses and loss expenses, end of year</span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">67,811</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">62,690 </span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">62,960 </span></td><td style="background-color:#cceeff;border-bottom:2pt solid #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div><div style="margin-top:3pt;padding-left:18pt;text-indent:-18pt"><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:4.55pt;font-weight:400;line-height:120%;position:relative;top:-2.44pt;vertical-align:baseline">(1)</span><span style="color:#000000;font-family:'News Gothic',sans-serif;font-size:7pt;font-weight:400;line-height:120%"> Net of valuation allowance for uncollectible reinsurance.</span></div>(2) Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments and earned premiums totaling $19 million, $53 million, and $85 million for 2020, 2019, and 2018, respectively.
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	62690000000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	62960000000	USD
CY2017Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	63179000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	14181000000	USD
CY2018Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	14689000000	USD
CY2017Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	14014000000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	48509000000	USD
CY2018Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	48271000000	USD
CY2017Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	49165000000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	22124000000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	19575000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	19048000000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-414000000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-845000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-981000000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	21710000000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	18730000000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	18067000000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	7782000000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	7894000000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	7544000000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	9652000000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	10579000000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	10796000000	USD
CY2020	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	17434000000	USD
CY2019	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	18473000000	USD
CY2018	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	18340000000	USD
CY2020Q4	cb	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Revaluation And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyRevaluationAndOther	379000000	USD
CY2019Q4	cb	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Revaluation And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyRevaluationAndOther	-19000000	USD
CY2018Q4	cb	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Revaluation And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyRevaluationAndOther	-621000000	USD
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CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	550000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	33000000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	517000000	USD
CY2019Q2	cb	Annualdividendpershareapprovedbyshareholders Annualdividendpershareapprovedbyshareholders	3.00
CY2018Q2	cb	Annualdividendpershareapprovedbyshareholders Annualdividendpershareapprovedbyshareholders	2.92
CY2019Q2	cb	Common Stock Dividend Rate Approved CommonStockDividendRateApproved	0.75
CY2018Q2	cb	Common Stock Dividend Rate Approved CommonStockDividendRateApproved	0.73
CY2020Q2	cb	Common Stock Dividend Rate Approved CommonStockDividendRateApproved	0.78
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	479783864	shares
CY2018Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	479783864	shares
CY2017Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	479783864	shares
CY2020	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	2178600	shares
CY2019	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	0	shares
CY2018	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	0	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	477605264	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	479783864	shares
CY2018Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	479783864	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	27812297	shares
CY2018Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	20580486	shares
CY2017Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	15950685	shares
CY2020	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	2345208	shares
CY2019	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	3210427	shares
CY2018	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	3089234	shares
CY2020	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	3584150	shares
CY2019	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	10442238	shares
CY2018	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	7719035	shares
CY2020	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	2178600	shares
CY2019	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	0	shares
CY2018	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	0	shares
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	26872639	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	27812297	shares
CY2018Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	20580486	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	450732625	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	451971567	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	459203378	shares
CY2020	us-gaap	Treasury Stock Shares Retired TreasuryStockSharesRetired	2178600	shares
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	24.15
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	24.15
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	24.15
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	24.15
CY2020	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	3584150	shares
CY2019	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	10442238	shares
CY2018	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	7719035	shares
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	516000000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1531000000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1021000000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	19000000	USD
CY2020Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	199000000	USD
CY2020	us-gaap	Common Stock Voting Rights CommonStockVotingRights	one
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	10000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	12000000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	10433316	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	99.20
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	1842690	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	143.07
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	29.71
CY2018	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1065384	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	73.57
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	71000000	USD
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	202900	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	133.92
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	11007722	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	108.25
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	2073940	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	133.90
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	18.76
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1944604	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	84.13
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	122000000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	251801	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	136.87
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	10885257	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	116.79
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	1958279	shares
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	206720	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	138.77
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	11478183	shares
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	100000000	USD
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	150.10
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	19.89
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1158633	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	86.90
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	76000000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	125.09
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	331000000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	7792343	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	116.35
CY2020Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	293000000	USD
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y9M18D
CY2020	cb	Restricted Stock Units Issued To Non Management Directors During Period Shares Restricted Stock Award RestrictedStockUnitsIssuedToNonManagementDirectorsDuringPeriodSharesRestrictedStockAward	27679	shares
CY2019	cb	Restricted Stock Units Issued To Non Management Directors During Period Shares Restricted Stock Award RestrictedStockUnitsIssuedToNonManagementDirectorsDuringPeriodSharesRestrictedStockAward	19019	shares
CY2018	cb	Restricted Stock Units Issued To Non Management Directors During Period Shares Restricted Stock Award RestrictedStockUnitsIssuedToNonManagementDirectorsDuringPeriodSharesRestrictedStockAward	20784	shares
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Purchase Price Of Common Stock Percent SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent	0.85
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Maximum Employee Subscription Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate	0.10
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	45000000	USD
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	41000000	USD
CY2018	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	37000000	USD
CY2020	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	383751	shares
CY2019	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	321800	shares
CY2018	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	347116	shares
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	211000000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	171000000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	171000000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	617000000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	1019000000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	514000000	USD
CY2020	cb	Gains Losses On Fair Value Changes In Separate Account Assets GainsLossesOnFairValueChangesInSeparateAccountAssets	58000000	USD
CY2019	cb	Gains Losses On Fair Value Changes In Separate Account Assets GainsLossesOnFairValueChangesInSeparateAccountAssets	44000000	USD
CY2018	cb	Gains Losses On Fair Value Changes In Separate Account Assets GainsLossesOnFairValueChangesInSeparateAccountAssets	-38000000	USD
CY2020	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	22000000	USD
CY2019	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	23000000	USD
CY2018	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	12000000	USD
CY2020	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	61000000	USD
CY2019	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-530000000	USD
CY2019	us-gaap	Interest Expense InterestExpense	552000000	USD
CY2019	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	42000000	USD
CY2018	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	30000000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	994000000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	596000000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	434000000	USD
CY2020	us-gaap	Premiums Written Net PremiumsWrittenNet	33820000000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	33117000000	USD
CY2020	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	21710000000	USD
CY2020	us-gaap	Liability For Future Policy Benefits Period Expense LiabilityForFuturePolicyBenefitsPeriodExpense	784000000	USD
CY2020	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	6547000000	USD
CY2020	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	2979000000	USD
CY2020	cb	Underwriting Income Loss Insurance UnderwritingIncomeLossInsurance	1097000000	USD
CY2020	us-gaap	Net Investment Income NetInvestmentIncome	3375000000	USD
CY2020	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	994000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	290000000	USD
CY2019	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	23000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	795000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	4454000000	USD
CY2018	us-gaap	Premiums Written Net PremiumsWrittenNet	30579000000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	30064000000	USD
CY2018	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	18067000000	USD
CY2019	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	6153000000	USD
CY2019	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	3030000000	USD
CY2018	us-gaap	Liability For Future Policy Benefits Period Expense LiabilityForFuturePolicyBenefitsPeriodExpense	590000000	USD
CY2020	cb	Segment Underwriting Income Lossand Net Investment Income Loss SegmentUnderwritingIncomeLossandNetInvestmentIncomeLoss	5176000000	USD
CY2020	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-498000000	USD
CY2020	us-gaap	Interest Expense InterestExpense	516000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	629000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3533000000	USD
CY2019	us-gaap	Premiums Written Net PremiumsWrittenNet	32275000000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	31290000000	USD
CY2019	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	18730000000	USD
CY2019	us-gaap	Liability For Future Policy Benefits Period Expense LiabilityForFuturePolicyBenefitsPeriodExpense	740000000	USD
CY2019	cb	Underwriting Income Loss Insurance UnderwritingIncomeLossInsurance	2637000000	USD
CY2019	us-gaap	Net Investment Income NetInvestmentIncome	3426000000	USD
CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	596000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	305000000	USD
CY2019	cb	Segment Underwriting Income Lossand Net Investment Income Loss SegmentUnderwritingIncomeLossandNetInvestmentIncomeLoss	6354000000	USD
CY2018	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	5912000000	USD
CY2018	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	2886000000	USD
CY2018	cb	Underwriting Income Loss Insurance UnderwritingIncomeLossInsurance	2609000000	USD
CY2018	us-gaap	Net Investment Income NetInvestmentIncome	3305000000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	434000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	339000000	USD
CY2018	cb	Segment Underwriting Income Lossand Net Investment Income Loss SegmentUnderwritingIncomeLossandNetInvestmentIncomeLoss	6009000000	USD
CY2018	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-652000000	USD
CY2018	us-gaap	Interest Expense InterestExpense	641000000	USD
CY2018	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	59000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	695000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	3962000000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	33117000000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	31290000000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	30064000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	3962000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3533000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	4454000000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	451602820	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	455910463	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	463629203	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1838692	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	3004200	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	3173145	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	453441512	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	458914663	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	466802348	shares
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.82
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	9.77
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	8.55
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.79
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	9.71
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	8.49
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	6811966	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	2410337	shares
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	3543188	shares
CY2020Q4	us-gaap	Statutory Accounting Practices Statutory Amount Available For Dividend Payments StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPayments	6400000000	USD
CY2020Q4	us-gaap	Statutory Accounting Practices Statutory Capital And Surplus Required StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired	29400000000	USD
CY2019Q4	us-gaap	Statutory Accounting Practices Statutory Capital And Surplus Required StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired	26700000000	USD
CY2020Q4	us-gaap	State Insurance Department Statutory To Naic Amount Of Reconciling Item StateInsuranceDepartmentStatutoryToNAICAmountOfReconcilingItem	140000000	USD
CY2019Q4	us-gaap	State Insurance Department Statutory To Naic Amount Of Reconciling Item StateInsuranceDepartmentStatutoryToNAICAmountOfReconcilingItem	147000000	USD
CY2020	us-gaap	Statutory Accounting Practices Permitted Practice Amount StatutoryAccountingPracticesPermittedPracticeAmount	55000000	USD
CY2019	us-gaap	Statutory Accounting Practices Permitted Practice Amount StatutoryAccountingPracticesPermittedPracticeAmount	54000000	USD
CY2020Q4	us-gaap	Investments Investments	118669000000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1747000000	USD
CY2020Q4	us-gaap	Restricted Cash RestrictedCash	89000000	USD
CY2020Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	10480000000	USD
CY2020Q4	cb	Reinsurance Recoverable Losses And Loss Expenses ReinsuranceRecoverableLossesAndLossExpenses	15592000000	USD
CY2020Q4	cb	Reinsurance Recoverable Future Policy Benefits ReinsuranceRecoverableFuturePolicyBenefits	206000000	USD
CY2020Q4	us-gaap	Value Of Business Acquired Voba ValueOfBusinessAcquiredVOBA	263000000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	190774000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	21211000000	USD
CY2020Q4	cb	Investments In Subsidiaries To Be Eliminated Upon Consolidation InvestmentsInSubsidiariesToBeEliminatedUponConsolidation	0	USD
CY2020Q4	us-gaap	Due From Affiliates DueFromAffiliates	0	USD
CY2020Q4	cb	Other Assets Condensed OtherAssetsCondensed	22517000000	USD
CY2020Q4	us-gaap	Assets Assets	190774000000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	67811000000	USD
CY2020Q4	us-gaap	Unearned Premiums UnearnedPremiums	17652000000	USD
CY2020Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	5713000000	USD
CY2020Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	0	USD
CY2020Q4	cb	Affiliatednotionalcashpoolingprograms Affiliatednotionalcashpoolingprograms	0	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	1405000000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	14948000000	USD
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CY2019	us-gaap	Sec Schedule1218 Supplemental Information Property Casualty Insurance Underwriters Current Year Claim And Claim Adjustment Expense SecSchedule1218SupplementalInformationPropertyCasualtyInsuranceUnderwritersCurrentYearClaimAndClaimAdjustmentExpense	19575000000	USD
CY2019	us-gaap	Sec Schedule1218 Supplemental Information Property Casualty Insurance Underwriters Prior Year Claim And Claim Adjustment Expense SecSchedule1218SupplementalInformationPropertyCasualtyInsuranceUnderwritersPriorYearClaimAndClaimAdjustmentExpense	-845000000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Amortization Of Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersAmortizationOfDeferredPolicyAcquisitionCosts	5831000000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Paid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPaidClaimsAndClaimsAdjustmentExpense	18473000000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Premiums Written SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPremiumsWritten	31126000000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDeferredPolicyAcquisitionCosts	3926000000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Reserves For Unpaid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersReservesForUnpaidClaimsAndClaimsAdjustmentExpense	48271000000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Unearned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersUnearnedPremiums	15532000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Amortization Of Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersAmortizationOfDeferredPolicyAcquisitionCosts	5630000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Paid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPaidClaimsAndClaimsAdjustmentExpense	18340000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Premiums Written SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPremiumsWritten	29505000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Earned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersEarnedPremiums	29042000000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Net Investment Income SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome	3047000000	USD
CY2018	us-gaap	Sec Schedule1218 Supplemental Information Property Casualty Insurance Underwriters Current Year Claim And Claim Adjustment Expense SecSchedule1218SupplementalInformationPropertyCasualtyInsuranceUnderwritersCurrentYearClaimAndClaimAdjustmentExpense	19048000000	USD
CY2018	us-gaap	Sec Schedule1218 Supplemental Information Property Casualty Insurance Underwriters Prior Year Claim And Claim Adjustment Expense SecSchedule1218SupplementalInformationPropertyCasualtyInsuranceUnderwritersPriorYearClaimAndClaimAdjustmentExpense	-981000000	USD

Files In Submission

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0000896159-21-000003-index.html	Edgar Link	pending
0000896159-21-000003.txt	Edgar Link	pending
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cb-12312020xex1078.htm	Edgar Link	pending
cb-12312020xex1079.htm	Edgar Link	pending
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FilingSummary.xml	Edgar Link	unprocessable
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MetaLinks.json	Edgar Link	pending
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report.css	Edgar Link	pending
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$CB
Chubb Ltd Stock $cb

2019 Q4 Form 10-K Financial Statement

#000089615921000003 Filed on February 25, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CB Chubb Ltd Stock $cb

2019 Q4 Form 10-K Financial Statement

#000089615921000003 Filed on February 25, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CB
Chubb Ltd Stock $cb