$CNA
CNA FINANCIAL CORP Stock $cna

$cna Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000002117524000007 Filed on February 06, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$3.444B	$3.507B	$13.30B
YoY Change	9.26%	12.73%	11.95%
Cost Of Revenue	$1.798B		$7.039B
YoY Change	9.23%		10.66%
Gross Profit	$1.646B		$6.260B
YoY Change	9.3%		13.45%
Gross Profit Margin	47.79%		47.07%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$16.00M	$29.00M	$73.00M
YoY Change	33.33%	123.08%	43.14%
% of Gross Profit	0.97%		1.17%
Operating Expenses	$2.982B	$3.013B	$11.65B
YoY Change	8.32%	8.03%	9.06%
Operating Profit	-$1.336B		-$5.394B
YoY Change	7.14%		4.37%
Interest Expense	$35.00M	-$34.00M	$127.0M
YoY Change	25.0%	21.43%	13.39%
% of Operating Profit
Other Income/Expense, Net	$85.00M		$274.0M
YoY Change	41.67%		-5.84%
Pretax Income	$427.0M	$460.0M	$1.518B
YoY Change	15.09%	56.46%	40.43%
Income Tax	$89.00M	$93.00M	$313.0M
% Of Pretax Income	20.84%	20.22%	20.62%
Net Earnings	$338.0M	$367.0M	$1.205B
YoY Change	13.8%	47.98%	34.79%
Net Earnings / Revenue	9.81%	10.46%	9.06%
Basic Earnings Per Share	$1.24		$4.44
Diluted Earnings Per Share	$1.24	$1.35	$4.43
COMMON SHARES
Basic Shares Outstanding	270.9M shares	270.9M shares	271.3M shares
Diluted Shares Outstanding	272.7M shares		272.2M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$409.0M	$345.0M
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	$256.0M	$253.0M	$393.0M
YoY Change	10.34%	11.95%	3.15%
Goodwill	$146.0M	$146.0M
YoY Change	0.69%	1.39%
Intangibles
YoY Change
Long-Term Investments	$46.67B	$46.56B	$46.56B
YoY Change	6.02%	7.84%	7.84%
Other Assets	$942.0M	$1.016B	$1.016B
YoY Change	-18.58%	-13.75%	-13.75%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$65.08B	$64.71B	$64.71B
YoY Change	4.87%	6.21%	6.21%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses			$215.0M
YoY Change			-2.27%
Deferred Revenue
YoY Change
Short-Term Debt	$550.0M	$550.0M	$0.00
YoY Change	126.34%	126.34%
Long-Term Debt Due	$550.0M	$550.0M	$550.0M
YoY Change	126.34%	126.34%	126.34%
Total Short-Term Liabilities	$550.0M	$550.0M	$765.0M
YoY Change	126.34%	126.34%	65.23%
LONG-TERM LIABILITIES
Long-Term Debt	$2.970B	$2.481B	$2.481B
YoY Change	16.98%	-2.25%	-2.25%
Other Long-Term Liabilities	$7.746B	$7.591B	$7.376B
YoY Change	1.39%	-1.38%	-1.35%
Total Long-Term Liabilities	$2.970B	$2.481B	$9.857B
YoY Change	16.98%	-2.25%	-1.58%
TOTAL LIABILITIES
Total Short-Term Liabilities	$550.0M	$550.0M	$765.0M
Total Long-Term Liabilities	$2.970B	$2.481B	$9.857B
Total Liabilities	$55.41B	$54.82B	$54.82B
YoY Change	3.79%	5.21%	5.21%
SHAREHOLDERS EQUITY
Retained Earnings	$9.425B	$9.755B
YoY Change	2.55%	1.91%
Common Stock	$2.884B	$2.904B
YoY Change	0.17%	0.03%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$75.00M	$94.00M
YoY Change	-21.05%	1.08%
Treasury Stock Shares
Shareholders Equity	$9.662B	$9.893B	$9.893B
YoY Change
Total Liabilities & Shareholders Equity	$65.08B	$64.71B	$64.71B
YoY Change	4.87%	6.21%	6.21%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$338.0M	$367.0M	$1.205B
YoY Change	13.8%	47.98%	34.79%
Depreciation, Depletion And Amortization	$16.00M	$29.00M	$73.00M
YoY Change	33.33%	123.08%	43.14%
Cash From Operating Activities	$504.0M	$520.0M	$2.285B
YoY Change	15.6%	1.56%	-8.67%
INVESTING ACTIVITIES
Capital Expenditures	$20.00M	$23.00M	$90.00M
YoY Change	0.0%	109.09%	73.08%
Acquisitions
YoY Change
Other Investing Activities	-$1.000M	-$283.0M	$5.000M
YoY Change	-101.41%	-34.03%	-50.0%
Cash From Investing Activities	-$249.0M	-$306.0M	-$1.843B
YoY Change	-588.24%	-30.45%	21.89%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$24.00M
YoY Change			-38.46%
Debt Paid & Issued, Net			$243.0M
YoY Change
Cash From Financing Activities	-$189.0M	-359.0M	-$577.0M
YoY Change	-60.63%	232.41%	-44.09%
NET CHANGE
Cash From Operating Activities	$504.0M	520.0M	$2.285B
Cash From Investing Activities	-$249.0M	-306.0M	-$1.843B
Cash From Financing Activities	-$189.0M	-359.0M	-$577.0M
Net Change In Cash	$64.00M	-145.0M	-$130.0M
YoY Change	700.0%	302.78%	113.11%
FREE CASH FLOW
Cash From Operating Activities	$504.0M	$520.0M	$2.285B
Capital Expenditures	$20.00M	$23.00M	$90.00M
Free Cash Flow	$484.0M	$497.0M	$2.195B
YoY Change	16.35%	-0.8%	-10.41%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0000021175
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CY2023Q4	us-gaap	Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#OtherAssets
CY2022Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#OtherLiabilities
CY2023Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#OtherLiabilities
CY2023	us-gaap	Fair Value Recurring Basis Unobservable Input Reconciliation Asset Gain Loss Statement Of Income Extensible List FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList	http://www.cna.com/20231231#InvestmentsandDerivativesRealizedGainLoss
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CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	1-5823
CY2023	dei	Entity Registrant Name EntityRegistrantName	CNA FINANCIAL CORPORATION
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	36-6169860
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	151 N. Franklin
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	60606
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Chicago,
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	IL
CY2023	dei	City Area Code CityAreaCode	312
CY2023	dei	Local Phone Number LocalPhoneNumber	822-5000
CY2023	dei	Security12b Title Security12bTitle	Common Stock, Par value $2.50
CY2023	dei	Trading Symbol TradingSymbol	CNA
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CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
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CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
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CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	296000000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	280000000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	253000000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	226000000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	146000000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	144000000	usd
CY2023Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	3661000000	usd
CY2022Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	3671000000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	2534000000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	2274000000	usd
CY2023Q4	us-gaap	Assets Assets	64711000000	usd
CY2022Q4	us-gaap	Assets Assets	61000000000	usd
CY2023Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	23304000000	usd
CY2022Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	22120000000	usd
CY2023Q4	us-gaap	Unearned Premiums UnearnedPremiums	6933000000	usd
CY2022Q4	us-gaap	Unearned Premiums UnearnedPremiums	6374000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	13959000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	13480000000	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	550000000	usd
CY2022Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	243000000	usd
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2481000000	usd
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2538000000	usd
CY2023Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	4694000000	usd
CY2022Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	4714000000	usd
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CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	2983000000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	54818000000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	52452000000	usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	2.50
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	2.50
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	273040243	shares
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	273040243	shares
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	270881457	shares
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	270895902	shares
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	683000000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	683000000	usd
CY2023Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	2221000000	usd
CY2022Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	2220000000	usd
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CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	9336000000	usd
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CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-3598000000	usd
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	2158786	shares
CY2022Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	2144341	shares
CY2023Q4	us-gaap	Treasury Stock Value TreasuryStockValue	94000000	usd
CY2022Q4	us-gaap	Treasury Stock Value TreasuryStockValue	93000000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	9893000000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	8548000000	usd
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CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	61000000000	usd
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CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2000000	usd
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CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	43000000	usd
CY2023	us-gaap	Increase Decrease In Financial Instruments Used In Operating Activities IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities	-1000000	usd
CY2022	us-gaap	Increase Decrease In Financial Instruments Used In Operating Activities IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities	-6000000	usd
CY2021	us-gaap	Increase Decrease In Financial Instruments Used In Operating Activities IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities	-20000000	usd
CY2023	cna	Net Realized Investment Gains Losses Continuing And Discontinuing Operations NetRealizedInvestmentGainsLossesContinuingAndDiscontinuingOperations	-99000000	usd
CY2022	cna	Net Realized Investment Gains Losses Continuing And Discontinuing Operations NetRealizedInvestmentGainsLossesContinuingAndDiscontinuingOperations	-199000000	usd
CY2021	cna	Net Realized Investment Gains Losses Continuing And Discontinuing Operations NetRealizedInvestmentGainsLossesContinuingAndDiscontinuingOperations	120000000	usd
CY2023	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	8000000	usd
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CY2022	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	129000000	usd
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CY2023	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	245000000	usd
CY2022	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	226000000	usd
CY2021	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	1358000000	usd
CY2023	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	41000000	usd
CY2022	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	29000000	usd
CY2021	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	-3000000	usd
CY2023	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	85000000	usd
CY2022	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	79000000	usd
CY2021	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	30000000	usd
CY2023	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	1667000000	usd
CY2022	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	2058000000	usd
CY2021	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	2485000000	usd
CY2023	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-192000000	usd
CY2022	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-192000000	usd
CY2021	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-76000000	usd
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CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	2502000000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1997000000	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	4029000000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	5909000000	usd
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CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	2358000000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	4464000000	usd
CY2023	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	317000000	usd
CY2022	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	509000000	usd
CY2021	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	316000000	usd
CY2023	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	164000000	usd
CY2022	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	138000000	usd
CY2021	us-gaap	Proceeds From Limited Partnership Investments ProceedsFromLimitedPartnershipInvestments	246000000	usd
CY2023	us-gaap	Proceeds From Sale And Collection Of Mortgage Notes Receivable ProceedsFromSaleAndCollectionOfMortgageNotesReceivable	122000000	usd
CY2022	us-gaap	Proceeds From Sale And Collection Of Mortgage Notes Receivable ProceedsFromSaleAndCollectionOfMortgageNotesReceivable	125000000	usd
CY2021	us-gaap	Proceeds From Sale And Collection Of Mortgage Notes Receivable ProceedsFromSaleAndCollectionOfMortgageNotesReceivable	190000000	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	6616000000	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	9821000000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	9307000000	usd
CY2023	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	293000000	usd
CY2022	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	294000000	usd
CY2023	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	402000000	usd
CY2021	us-gaap	Payments To Acquire Mortgage Notes Receivable PaymentsToAcquireMortgageNotesReceivable	95000000	usd
CY2022	cna	Change In Other Investments ChangeInOtherInvestments	8000000	usd
CY2021	cna	Change In Other Investments ChangeInOtherInvestments	-6000000	usd
CY2023	cna	Change In Short Term Investments ChangeInShortTermInvestments	-274000000	usd
CY2022	cna	Change In Short Term Investments ChangeInShortTermInvestments	155000000	usd
CY2021	cna	Change In Short Term Investments ChangeInShortTermInvestments	-83000000	usd
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	90000000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	52000000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	26000000	usd
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CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1512000000	usd
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CY2023	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	787000000	usd
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CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	621000000	usd
CY2023	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	491000000	usd
CY2022	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	usd
CY2021	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	usd
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CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	24000000	usd
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CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-1032000000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-648000000	usd
CY2023	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	5000000	usd
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CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-130000000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-61000000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	117000000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	475000000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	536000000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	419000000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	345000000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	475000000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	536000000	usd
CY2023	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.88
CY2022	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	3.60
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.27
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	9893000000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	8548000000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	11105000000	usd
CY2023	us-gaap	Use Of Estimates UseOfEstimates	The preparation of Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates.
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CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	814000000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	132000000	usd
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CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-89000000	usd
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CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	43000000	usd
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CY2022	cna	Structured Settlement Annuities Interest Rates Low End StructuredSettlementAnnuitiesInterestRatesLowEnd	0.064
CY2023	cna	Structured Settlement Annuities Interest Rates Low End StructuredSettlementAnnuitiesInterestRatesLowEnd	0.064
CY2023Q4	cna	Discounted Reserves For Unfunded Structured Settlements DiscountedReservesForUnfundedStructuredSettlements	465000000	usd
CY2022Q4	cna	Discounted Reserves For Unfunded Structured Settlements DiscountedReservesForUnfundedStructuredSettlements	485000000	usd
CY2023Q4	cna	Discounted Reserves For Unfunded Structure Settlements Discount Amount DiscountedReservesForUnfundedStructureSettlementsDiscountAmount	559000000	usd
CY2022Q4	cna	Discounted Reserves For Unfunded Structure Settlements Discount Amount DiscountedReservesForUnfundedStructureSettlementsDiscountAmount	590000000	usd
CY2023Q4	cna	Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements	34000000	usd
CY2022Q4	cna	Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements	36000000	usd
CY2021Q4	cna	Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements Amountofinterestrecognizedonthediscountedreservesofunfundedstructuredsettlements	36000000	usd
CY2023	us-gaap	Workers Compensation Discount Percent WorkersCompensationDiscountPercent	0.035
CY2022	us-gaap	Workers Compensation Discount Percent WorkersCompensationDiscountPercent	0.035
CY2023Q4	us-gaap	Workers Compensation Liability Current And Noncurrent WorkersCompensationLiabilityCurrentAndNoncurrent	196000000	usd
CY2022Q4	us-gaap	Workers Compensation Liability Current And Noncurrent WorkersCompensationLiabilityCurrentAndNoncurrent	211000000	usd
CY2023Q4	cna	Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves	9000000	usd
CY2022Q4	cna	Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves	9000000	usd
CY2021Q4	cna	Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves Amountofinterestaccretionrecognizedonthediscountedreservesofworkerscompensationlifetimeclaimreserves	12000000	usd
CY2023	cna	Future Policy Benefit Reserves Cash Flows Projected To Occur Beyond Tenor With Market Observable Rates Available Grading Period FuturePolicyBenefitReservesCashFlowsProjectedToOccurBeyondTenorWithMarketObservableRatesAvailableGradingPeriod	P10Y
CY2023	us-gaap	Loss Contingency Undiscounted Amount Of Insurance Related Assessment Liability LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiability	84000000	usd
CY2022	us-gaap	Loss Contingency Undiscounted Amount Of Insurance Related Assessment Liability LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiability	74000000	usd
CY2023	cna	Percentage Of Billed Receivables Compared To Total Reinsurance Receivable PercentageOfBilledReceivablesComparedToTotalReinsuranceReceivable	0.05
CY2023	us-gaap	Policyholder Dividends Rate On Policy Earnings PolicyholderDividendsRateOnPolicyEarnings	0.02
CY2022	us-gaap	Policyholder Dividends Rate On Policy Earnings PolicyholderDividendsRateOnPolicyEarnings	0.02
CY2021	us-gaap	Policyholder Dividends Rate On Policy Earnings PolicyholderDividendsRateOnPolicyEarnings	0.01
CY2023	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	9000000	usd
CY2022	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-22000000	usd
CY2021	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-1000000	usd
CY2022	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1000000	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1000000	shares
CY2023	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1000000	shares
CY2023	us-gaap	Interest Paid Net InterestPaidNet	124000000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	109000000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	110000000	usd
CY2023	us-gaap	Income Taxes Paid IncomeTaxesPaid	282000000	usd
CY2022	us-gaap	Income Taxes Paid IncomeTaxesPaid	277000000	usd
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	278000000	usd
CY2023	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	2343000000	usd
CY2022	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	1877000000	usd
CY2021	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	2223000000	usd
CY2023	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	79000000	usd
CY2022	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	72000000	usd
CY2021	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	64000000	usd
CY2023	us-gaap	Net Investment Income NetInvestmentIncome	2264000000	usd
CY2022	us-gaap	Net Investment Income NetInvestmentIncome	1805000000	usd
CY2021	us-gaap	Net Investment Income NetInvestmentIncome	2159000000	usd
CY2022Q4	cna	Non Income Producing Fixed Maturity Securities NonIncomeProducingFixedMaturitySecurities	0	usd
CY2023Q4	cna	Non Income Producing Fixed Maturity Securities NonIncomeProducingFixedMaturitySecurities	0	usd
CY2023Q4	cna	Non Income Producing Mortgage Loans NonIncomeProducingMortgageLoans	20000000	usd
CY2022Q4	cna	Non Income Producing Mortgage Loans NonIncomeProducingMortgageLoans	7000000	usd
CY2022Q4	cna	Investmentsthat Exceed Ten Percentof Stockholders Equity InvestmentsthatExceedTenPercentofStockholdersEquity	0	usd
CY2023Q4	cna	Investmentsthat Exceed Ten Percentof Stockholders Equity InvestmentsthatExceedTenPercentofStockholdersEquity	0	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	75000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	120000000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	186000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	166000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	261000000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	90000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-91000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-141000000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	96000000	usd
CY2023	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	4000000	usd
CY2022	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	-116000000	usd
CY2021	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	4000000	usd
CY2023	us-gaap	Gain Loss On Sale Of Derivatives GainLossOnSaleOfDerivatives	-1000000	usd
CY2022	us-gaap	Gain Loss On Sale Of Derivatives GainLossOnSaleOfDerivatives	64000000	usd
CY2021	us-gaap	Gain Loss On Sale Of Derivatives GainLossOnSaleOfDerivatives	6000000	usd
CY2023	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	11000000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	8000000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-10000000	usd
CY2023	cna	Realized Gain Losson Short Term Investments RealizedGainLossonShortTermInvestments	0	usd
CY2022	cna	Realized Gain Losson Short Term Investments RealizedGainLossonShortTermInvestments	2000000	usd
CY2021	cna	Realized Gain Losson Short Term Investments RealizedGainLossonShortTermInvestments	4000000	usd
CY2023	cna	Investmentsand Derivatives Realized Gain Loss InvestmentsandDerivativesRealizedGainLoss	-99000000	usd
CY2022	cna	Investmentsand Derivatives Realized Gain Loss InvestmentsandDerivativesRealizedGainLoss	-199000000	usd
CY2021	cna	Investmentsand Derivatives Realized Gain Loss InvestmentsandDerivativesRealizedGainLoss	120000000	usd
CY2022	cna	Investment And Derivative Realized Gain Loss Coinsurance Agreement InvestmentAndDerivativeRealizedGainLossCoinsuranceAgreement	18000000	usd
CY2022	cna	Investment And Derivative Realized Gain Loss Coinsurance Agreement InvestmentAndDerivativeRealizedGainLossCoinsuranceAgreement	18000000	usd
CY2023	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	44000000	usd
CY2022	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	62000000	usd
CY2021	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	31000000	usd
CY2023	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	11000000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	8000000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-10000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	42414000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1022000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2995000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	16000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	40425000000	usd
CY2023Q4	us-gaap	Trading Securities Debt Amortized Cost TradingSecuritiesDebtAmortizedCost	0	usd
CY2023Q4	us-gaap	Trading Securities Debt TradingSecuritiesDebt	0	usd
CY2023Q4	cna	Debt Securities Amortized Cost DebtSecuritiesAmortizedCost	42414000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1022000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2995000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	16000000	usd
CY2023Q4	us-gaap	Debt Securities DebtSecurities	40425000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	41032000000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	652000000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	4056000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	37627000000	usd
CY2022Q4	us-gaap	Trading Securities Debt Amortized Cost TradingSecuritiesDebtAmortizedCost	0	usd
CY2022Q4	us-gaap	Trading Securities Debt TradingSecuritiesDebt	0	usd
CY2022Q4	cna	Debt Securities Amortized Cost DebtSecuritiesAmortizedCost	41032000000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	652000000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	4056000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1000000	usd
CY2022Q4	us-gaap	Debt Securities DebtSecurities	37627000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	3483000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	74000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	22248000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	2921000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	25731000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	2995000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	25234000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	2946000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	4277000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	1110000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	29511000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	25731000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	2995000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	29511000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	4056000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded	17000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Purchased With Credit Deterioration Increase DebtSecuritiesAvailableForSaleAllowanceForCreditLossPurchasedWithCreditDeteriorationIncrease	22000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Securities Sold DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold	6000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Sell Before Recovery DebtSecuritiesAvailableForSaleAllowanceForCreditLossSellBeforeRecovery	8000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Writeoff DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff	15000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Recovery DebtSecuritiesAvailableForSaleAllowanceForCreditLossRecovery	0	usd
CY2023	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not To Sell Before Recovery Credit Loss Previously Recorded Expense Reversal DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal	5000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	16000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	18000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Purchased With Credit Deterioration Increase DebtSecuritiesAvailableForSaleAllowanceForCreditLossPurchasedWithCreditDeteriorationIncrease	3000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Securities Sold DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Sell Before Recovery DebtSecuritiesAvailableForSaleAllowanceForCreditLossSellBeforeRecovery	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Writeoff DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff	12000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Recovery DebtSecuritiesAvailableForSaleAllowanceForCreditLossRecovery	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not To Sell Before Recovery Credit Loss Previously Recorded Expense Reversal DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal	-8000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	1121000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	1091000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	1012000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	1001000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	11563000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	11180000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	9880000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	9399000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	13359000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	12573000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	13788000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	12453000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	16371000000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	15581000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	16352000000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	14774000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	42414000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	40425000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	41032000000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	37627000000	usd
CY2023Q4	cna	Limited Partnership Investments LimitedPartnershipInvestments	2174000000	usd
CY2022Q4	cna	Limited Partnership Investments LimitedPartnershipInvestments	1926000000	usd
CY2023Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	250000000	usd
CY2022Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	176000000	usd
CY2023Q4	cna	Percentage Of Limited Partnerships Reported On Current Basis PercentageOfLimitedPartnershipsReportedOnCurrentBasis	0.17
CY2023Q4	cna	Percentage Of Limited Partnerships Reported On One Month Lag PercentageOfLimitedPartnershipsReportedOnOneMonthLag	0.04
CY2023Q4	cna	Limited Partnerships Invested In Private Debt And Equity LimitedPartnershipsInvestedInPrivateDebtAndEquity	0.85
CY2022Q4	cna	Limited Partnerships Invested In Private Debt And Equity LimitedPartnershipsInvestedInPrivateDebtAndEquity	0.76
CY2023Q4	cna	Percentage Of Limited Partnerships Employing Hedge Fund Strategies Focused On Fixed Income And Equity Investments PercentageOfLimitedPartnershipsEmployingHedgeFundStrategiesFocusedOnFixedIncomeAndEquityInvestments	0.15
CY2022Q4	cna	Percentage Of Limited Partnerships Employing Hedge Fund Strategies Focused On Fixed Income And Equity Investments PercentageOfLimitedPartnershipsEmployingHedgeFundStrategiesFocusedOnFixedIncomeAndEquityInvestments	0.24
CY2023Q4	cna	Carrying Value Of Ten Largest Limited Partnerships CarryingValueOfTenLargestLimitedPartnerships	622000000	usd
CY2022Q4	cna	Carrying Value Of Ten Largest Limited Partnerships CarryingValueOfTenLargestLimitedPartnerships	633000000	usd
CY2022Q4	cna	Carrying Value Of Limited Partnerships As Percentage Of Aggregate Partnership Equity CarryingValueOfLimitedPartnershipsAsPercentageOfAggregatePartnershipEquity	0.01
CY2023Q4	cna	Carrying Value Of Limited Partnerships As Percentage Of Aggregate Partnership Equity CarryingValueOfLimitedPartnershipsAsPercentageOfAggregatePartnershipEquity	0.01
CY2023Q4	cna	Income As Percentage Of Change In Partnership Equity For All Limited Partnerships IncomeAsPercentageOfChangeInPartnershipEquityForAllLimitedPartnerships	0.01
CY2022Q4	cna	Income As Percentage Of Change In Partnership Equity For All Limited Partnerships IncomeAsPercentageOfChangeInPartnershipEquityForAllLimitedPartnerships	0.02
CY2021Q4	cna	Income As Percentage Of Change In Partnership Equity For All Limited Partnerships IncomeAsPercentageOfChangeInPartnershipEquityForAllLimitedPartnerships	0.02
CY2023Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	1000000	usd
CY2022Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	usd
CY2023Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	usd
CY2023	cna	Increase Decrease Fixed Maturity Securities IncreaseDecreaseFixedMaturitySecurities	-224000000	usd
CY2023	cna	Increase Decrease Short Term Investments IncreaseDecreaseShortTermInvestments	-4000000	usd
CY2023	cna	Increase Decrease Accrued Investment Income IncreaseDecreaseAccruedInvestmentIncome	-2000000	usd
CY2023	cna	Increase Decrease Funds Withheld Liability IncreaseDecreaseFundsWithheldLiability	-216000000	usd
CY2023Q4	us-gaap	Embedded Derivative Fair Value Of Embedded Derivative Liability EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability	14000000	usd
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CY2023	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-top:6pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves.</span></div><div style="margin-top:5pt"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:100.000%"><tr><td style="width:1.0%"></td><td style="width:64.066%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:9.733%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.966%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:9.733%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.966%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:9.736%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">As of or for the years ended December 31</span></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(In millions)</span></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2023</span></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2022</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:700;line-height:100%;position:relative;top:-2.8pt;vertical-align:baseline"> (1)</span></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2021</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:700;line-height:100%;position:relative;top:-2.8pt;vertical-align:baseline"> (1)</span></div></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Reserves, beginning of year:</span></td><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000;padding:0 1pt"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Gross</span></td><td style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">22,120 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">21,269 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">19,862 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Ceded</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,191 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">4,969 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">4,005 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Net reserves, beginning of year</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">16,929 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">16,300 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">15,857 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Reduction of net reserves due to Excess Workers' Compensation Loss Portfolio Transfer</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:'Times New Roman',sans-serif;font-size:8pt;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><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;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><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(632)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Net incurred claim and claim adjustment expenses:</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Provision for insured events of 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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,667 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,181 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,021 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Increase (decrease) in provision for insured events of 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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">48 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(32)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">15 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Amortization of discount</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">44 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">44 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">48 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Total net incurred </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:100%;position:relative;top:-2.8pt;vertical-align:baseline">(2)</span></div></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,759 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,193 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,084 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Net payments attributable to:</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Current year events</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(922)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(821)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(933)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Prior year events</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(3,679)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(3,481)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(3,016)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Total net payments</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(4,601)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(4,302)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(3,949)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Foreign currency translation adjustment and other</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">76 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(262)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(60)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Net reserves, end of year</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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">18,163 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">16,929 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">16,300 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Ceded reserves, end of 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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,141 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">5,191 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"></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:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">4,969 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Gross reserves, end of year</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">23,304 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">22,120 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">21,269 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"></td></tr></table></div><div style="margin-bottom:6pt;margin-top:6pt;padding-left:13.5pt;text-align:justify;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(1) In conjunction with the Company's adoption of ASU 2018-12, at January 1, 2023, long-term care reserves for policyholders currently receiving benefits were reclassified from Claim and claim adjustment expenses into Future policy benefits and this change was applied retrospectively as of January 1, 2021. See Note A to the Consolidated Financial Statements for additional information. </span></div><div style="margin-top:1pt;padding-left:13.5pt;text-align:justify;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(2) Total net incurred does not agree to Insurance claims and policyholders' benefits as reflected on the Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, the loss on the Excess Workers' Compensation LPT (EWC LPT) and uncollectible reinsurance, which are not reflected in the table above.</span></div>
CY2022Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	22120000000	usd
CY2021Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	21269000000	usd
CY2020Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	19862000000	usd
CY2022Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	5191000000	usd
CY2021Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	4969000000	usd
CY2020Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	4005000000	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	16929000000	usd
CY2021Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	16300000000	usd
CY2020Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	15857000000	usd
CY2023Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Opening Balance Adjustments LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseOpeningBalanceAdjustments	0	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Opening Balance Adjustments LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseOpeningBalanceAdjustments	0	usd
CY2021Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Opening Balance Adjustments LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseOpeningBalanceAdjustments	-632000000	usd
CY2022	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	5181000000	usd
CY2021	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	5021000000	usd
CY2022	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-32000000	usd
CY2021	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	15000000	usd
CY2023	cna	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Amortization Of Discount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsAmortizationOfDiscount	44000000	usd
CY2022	cna	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Amortization Of Discount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsAmortizationOfDiscount	44000000	usd
CY2021	cna	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Amortization Of Discount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsAmortizationOfDiscount	48000000	usd
CY2023	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	5759000000	usd
CY2022	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	5193000000	usd
CY2021	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	5084000000	usd
CY2023	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	922000000	usd
CY2022	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	821000000	usd
CY2021	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	933000000	usd
CY2023	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	3679000000	usd
CY2022	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	3481000000	usd
CY2021	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	3016000000	usd
CY2023	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	4601000000	usd
CY2022	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	4302000000	usd
CY2021	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3949000000	usd
CY2023	cna	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Cta And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCtaAndOther	76000000	usd
CY2022	cna	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Cta And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCtaAndOther	-262000000	usd
CY2021	cna	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Cta And Other LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCtaAndOther	-60000000	usd
CY2023Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	18163000000	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	16929000000	usd
CY2021Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	16300000000	usd
CY2023Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	5141000000	usd
CY2022Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	5191000000	usd
CY2021Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	4969000000	usd
CY2023Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	23304000000	usd
CY2022Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	22120000000	usd
CY2021Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	21269000000	usd
CY2023Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Reported Claims Amount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseReportedClaimsAmount	7738000000	usd
CY2023Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Amount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsAmount	15566000000	usd
CY2023Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	23304000000	usd
CY2023Q4	cna	Net Case Reserves NetCaseReserves	5663000000	usd
CY2023Q4	cna	Net Ibnr Reserves NetIbnrReserves	12500000000	usd
CY2023Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	18163000000	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Reported Claims Amount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseReportedClaimsAmount	7577000000	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Amount LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsAmount	14543000000	usd
CY2022Q4	cna	Liabilityforunpaidclaimandclaimadjustmentexpensegross Liabilityforunpaidclaimandclaimadjustmentexpensegross	22120000000	usd
CY2022Q4	cna	Net Case Reserves NetCaseReserves	5509000000	usd
CY2022Q4	cna	Net Ibnr Reserves NetIbnrReserves	11420000000	usd
CY2022Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	16929000000	usd
CY2023	cna	Pretax Favorable Unfavorable Premium Development Excluding Life Group PretaxFavorableUnfavorablePremiumDevelopmentExcludingLifeGroup	48000000	usd
CY2022	cna	Pretax Favorable Unfavorable Premium Development Excluding Life Group PretaxFavorableUnfavorablePremiumDevelopmentExcludingLifeGroup	-32000000	usd
CY2021	cna	Pretax Favorable Unfavorable Premium Development Excluding Life Group PretaxFavorableUnfavorablePremiumDevelopmentExcludingLifeGroup	11000000	usd
CY2021Q1	us-gaap	Funds Held Under Reinsurance Agreements Liability FundsHeldUnderReinsuranceAgreementsLiability	690000000	usd
CY2021Q1	cna	Retroactive Reinsurance Agreement Maximum RetroactiveReinsuranceAgreementMaximum	1000000000	usd
CY2021Q1	cna	Reinsurance Premiums Paid ReinsurancePremiumsPaid	697000000	usd
	cna	Reinsurance Premiums Paid ReinsurancePremiumsPaid	64000000	usd
CY2021Q1	us-gaap	Reinsurance Loss On Uncollectible Accounts In Period Amount ReinsuranceLossOnUncollectibleAccountsInPeriodAmount	12000000	usd
CY2023Q4	us-gaap	Securities Held As Collateral At Fair Value SecuritiesHeldAsCollateralAtFairValue	440000000	usd
CY2023Q3	cna	Liability For Unpaid Claims And Claims Adjustment Expense Long Term Care Policies Period Increase Decrease LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseLongTermCarePoliciesPeriodIncreaseDecrease	8000000	usd
CY2022Q3	cna	Liability For Unpaid Claims And Claims Adjustment Expense Long Term Care Policies Period Increase Decrease LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseLongTermCarePoliciesPeriodIncreaseDecrease	186000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	3991000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	4735000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	5086000000	usd
CY2022Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	74000000	usd
CY2021Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	880000000	usd
CY2020Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	1140000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3917000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3855000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3946000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseFromCashFlowChange	28000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseFromCashFlowChange	352000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseFromCashFlowChange	173000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-126000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-49000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedNetPremiumCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-24000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	3819000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	4158000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	4095000000	usd
CY2023	us-gaap	Liability For Future Policy Benefit Expected Net Premium Interest Income LiabilityForFuturePolicyBenefitExpectedNetPremiumInterestIncome	202000000	usd
CY2022	us-gaap	Liability For Future Policy Benefit Expected Net Premium Interest Income LiabilityForFuturePolicyBenefitExpectedNetPremiumInterestIncome	216000000	usd
CY2021	us-gaap	Liability For Future Policy Benefit Expected Net Premium Interest Income LiabilityForFuturePolicyBenefitExpectedNetPremiumInterestIncome	219000000	usd
CY2023	us-gaap	Liability For Future Policy Benefit Expected Net Premium Net Premium Collected LiabilityForFuturePolicyBenefitExpectedNetPremiumNetPremiumCollected	436000000	usd
CY2022	us-gaap	Liability For Future Policy Benefit Expected Net Premium Net Premium Collected LiabilityForFuturePolicyBenefitExpectedNetPremiumNetPremiumCollected	457000000	usd
CY2021	us-gaap	Liability For Future Policy Benefit Expected Net Premium Net Premium Collected LiabilityForFuturePolicyBenefitExpectedNetPremiumNetPremiumCollected	459000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3585000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3917000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedNetPremiumOriginalDiscountRateBeforeCashFlowAndReinsurance	3855000000	usd
CY2023Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	125000000	usd
CY2022Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	74000000	usd
CY2021Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Net Premium Before Tax AociLiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeTax	880000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	3710000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	3991000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Net Premium Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedNetPremiumBeforeReinsuranceAfterDiscountRateChange	4735000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	17471000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	22745000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	23955000000	usd
CY2022Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-125000000	usd
CY2021Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-5942000000	usd
CY2020Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-7395000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	17346000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	16803000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	16560000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseFromCashFlowChange	36000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseFromCashFlowChange	538000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease From Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseFromCashFlowChange	176000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-46000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-21000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Cumulative Increase Decrease Of Actual Variance From Expected Experience LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitCumulativeIncreaseDecreaseOfActualVarianceFromExpectedExperience	-19000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Benefit Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFutureBenefitOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	17336000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Benefit Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFutureBenefitOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	17320000000	usd
CY2020Q4	us-gaap	Liability For Future Policy Benefit Expected Future Benefit Original Discount Rate Before Reinsurance After Cash Flow Change LiabilityForFuturePolicyBenefitExpectedFutureBenefitOriginalDiscountRateBeforeReinsuranceAfterCashFlowChange	16717000000	usd
CY2023	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitInterestExpense	962000000	usd
CY2022	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitInterestExpense	979000000	usd
CY2021	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitInterestExpense	973000000	usd
CY2023	us-gaap	Liability For Future Policy Benefits Payment For Benefits LiabilityForFuturePolicyBenefitsPaymentForBenefits	1207000000	usd
CY2022	us-gaap	Liability For Future Policy Benefits Payment For Benefits LiabilityForFuturePolicyBenefitsPaymentForBenefits	953000000	usd
CY2021	us-gaap	Liability For Future Policy Benefits Payment For Benefits LiabilityForFuturePolicyBenefitsPaymentForBenefits	887000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	17091000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	17346000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Original Discount Rate Before Cash Flow And Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitOriginalDiscountRateBeforeCashFlowAndReinsurance	16803000000	usd
CY2023Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-578000000	usd
CY2022Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-125000000	usd
CY2021Q4	us-gaap	Aoci Liability For Future Policy Benefit Expected Future Policy Benefit Before Tax AociLiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeTax	-5942000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	17669000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	17471000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Before Reinsurance After Discount Rate Change LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitBeforeReinsuranceAfterDiscountRateChange	22745000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	13959000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	13480000000	usd
CY2021Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	18010000000	usd
CY2023	cna	Insurance Claims And Policyholders Benefits Including Policyholders Dividends Remeasurement Impact InsuranceClaimsAndPolicyholdersBenefitsIncludingPolicyholdersDividendsRemeasurementImpact	-88000000	usd
CY2022	cna	Insurance Claims And Policyholders Benefits Including Policyholders Dividends Remeasurement Impact InsuranceClaimsAndPolicyholdersBenefitsIncludingPolicyholdersDividendsRemeasurementImpact	-214000000	usd
CY2021	cna	Insurance Claims And Policyholders Benefits Including Policyholders Dividends Remeasurement Impact InsuranceClaimsAndPolicyholdersBenefitsIncludingPolicyholdersDividendsRemeasurementImpact	-8000000	usd
CY2023	us-gaap	Liability For Future Policy Benefit Gross Premium Income LiabilityForFuturePolicyBenefitGrossPremiumIncome	451000000	usd
CY2022	us-gaap	Liability For Future Policy Benefit Gross Premium Income LiabilityForFuturePolicyBenefitGrossPremiumIncome	473000000	usd
CY2021	us-gaap	Liability For Future Policy Benefit Gross Premium Income LiabilityForFuturePolicyBenefitGrossPremiumIncome	491000000	usd
CY2023	us-gaap	Liability For Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitInterestExpense	760000000	usd
CY2022	us-gaap	Liability For Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitInterestExpense	763000000	usd
CY2021	us-gaap	Liability For Future Policy Benefit Interest Expense LiabilityForFuturePolicyBenefitInterestExpense	754000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Undiscounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitUndiscountedBeforeReinsurance	32851000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Policy Benefit Undiscounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitUndiscountedBeforeReinsurance	34261000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Future Gross Premium Undiscounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFutureGrossPremiumUndiscountedBeforeReinsurance	5414000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Gross Premium Undiscounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFutureGrossPremiumUndiscountedBeforeReinsurance	5910000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Expected Future Gross Premium Discounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFutureGrossPremiumDiscountedBeforeReinsurance	3824000000	usd
CY2022Q4	us-gaap	Liability For Future Policy Benefit Expected Future Gross Premium Discounted Before Reinsurance LiabilityForFuturePolicyBenefitExpectedFutureGrossPremiumDiscountedBeforeReinsurance	4070000000	usd
CY2023Q4	us-gaap	Liability For Future Policy Benefit Weighted Average Duration LiabilityForFuturePolicyBenefitWeightedAverageDuration	P11Y
CY2022Q4	us-gaap	Liability For Future Policy Benefit Weighted Average Duration LiabilityForFuturePolicyBenefitWeightedAverageDuration	P12Y
CY2023Q4	us-gaap	Liability For Future Policy Benefit Weighted Average Interest Accretion Rate LiabilityForFuturePolicyBenefitWeightedAverageInterestAccretionRate	0.0522
CY2022Q4	us-gaap	Liability For Future Policy Benefit Weighted Average Interest Accretion Rate LiabilityForFuturePolicyBenefitWeightedAverageInterestAccretionRate	0.0527
CY2023Q4	us-gaap	Liability For Future Policy Benefit Current Weighted Average Discount Rate LiabilityForFuturePolicyBenefitCurrentWeightedAverageDiscountRate	0.0494
CY2022Q4	us-gaap	Liability For Future Policy Benefit Current Weighted Average Discount Rate LiabilityForFuturePolicyBenefitCurrentWeightedAverageDiscountRate	0.0523
CY2023	cna	Liability For Future Policy Benefit Losses Recognized In Current Period Reversed Due To Favorable Development LiabilityForFuturePolicyBenefitLossesRecognizedInCurrentPeriodReversedDueToFavorableDevelopment	164000000	usd
CY2022	cna	Liability For Future Policy Benefit Losses Recognized In Current Period Reversed Due To Favorable Development LiabilityForFuturePolicyBenefitLossesRecognizedInCurrentPeriodReversedDueToFavorableDevelopment	178000000	usd
CY2023	cna	Liability For Future Policy Benefit Losses Recognized In Prior Period Reversed Due To Favorable Development LiabilityForFuturePolicyBenefitLossesRecognizedInPriorPeriodReversedDueToFavorableDevelopment	42000000	usd
CY2022	cna	Liability For Future Policy Benefit Losses Recognized In Prior Period Reversed Due To Favorable Development LiabilityForFuturePolicyBenefitLossesRecognizedInPriorPeriodReversedDueToFavorableDevelopment	12000000	usd
CY2023Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	5141000000	usd
CY2022Q4	cna	Ceded Claim And Claim Adjustment Expenses CededClaimAndClaimAdjustmentExpenses	5191000000	usd
CY2023Q4	us-gaap	Reinsurance Recoverables On Paid Losses Gross ReinsuranceRecoverablesOnPaidLossesGross	293000000	usd
CY2022Q4	us-gaap	Reinsurance Recoverables On Paid Losses Gross ReinsuranceRecoverablesOnPaidLossesGross	247000000	usd
CY2023Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	5434000000	usd
CY2022Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	5438000000	usd
CY2023Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	22000000	usd
CY2022Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	22000000	usd
CY2023Q4	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	5412000000	usd
CY2022Q4	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	5416000000	usd
CY2023Q4	cna	Voluntary Reinsurance Recoverable Gross VoluntaryReinsuranceRecoverableGross	4823000000	usd
CY2023Q4	us-gaap	Funds Held Under Reinsurance Agreements Liability FundsHeldUnderReinsuranceAgreementsLiability	3600000000	usd
CY2022Q4	us-gaap	Funds Held Under Reinsurance Agreements Liability FundsHeldUnderReinsuranceAgreementsLiability	3700000000	usd
CY2023	us-gaap	Direct Premiums Earned DirectPremiumsEarned	14315000000	usd
CY2023	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	267000000	usd
CY2023	us-gaap	Ceded Premiums Earned CededPremiumsEarned	5102000000	usd
CY2023	us-gaap	Premiums Earned Net PremiumsEarnedNet	9480000000	usd
CY2022	us-gaap	Direct Premiums Earned DirectPremiumsEarned	13524000000	usd
CY2022	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	277000000	usd
CY2022	us-gaap	Ceded Premiums Earned CededPremiumsEarned	5134000000	usd
CY2022	us-gaap	Premiums Earned Net PremiumsEarnedNet	8667000000	usd
CY2021	us-gaap	Direct Premiums Earned DirectPremiumsEarned	12997000000	usd
CY2021	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	288000000	usd
CY2021	us-gaap	Ceded Premiums Earned CededPremiumsEarned	5110000000	usd
CY2021	us-gaap	Premiums Earned Net PremiumsEarnedNet	8175000000	usd
CY2023	us-gaap	Direct Premiums Written DirectPremiumsWritten	14902000000	usd
CY2023	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	262000000	usd
CY2023	us-gaap	Ceded Premiums Written CededPremiumsWritten	5272000000	usd
CY2023	us-gaap	Premiums Written Net PremiumsWrittenNet	9892000000	usd
CY2022	us-gaap	Direct Premiums Written DirectPremiumsWritten	14264000000	usd
CY2022	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	281000000	usd
CY2022	us-gaap	Ceded Premiums Written CededPremiumsWritten	5417000000	usd
CY2022	us-gaap	Premiums Written Net PremiumsWrittenNet	9128000000	usd
CY2021	us-gaap	Direct Premiums Written DirectPremiumsWritten	13587000000	usd
CY2021	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	303000000	usd
CY2021	us-gaap	Ceded Premiums Written CededPremiumsWritten	5485000000	usd
CY2021	us-gaap	Premiums Written Net PremiumsWrittenNet	8405000000	usd
CY2023	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	2772000000	usd
CY2022	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	2631000000	usd
CY2021	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	3058000000	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	550000000	usd
CY2022Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	243000000	usd
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2481000000	usd
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2538000000	usd
CY2023Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	3031000000	usd
CY2022Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	2781000000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	5000000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Maximum Amount Available FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresMaximumAmountAvailable	106000000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	0	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	0	usd
CY2023	us-gaap	Debt Instrument Term DebtInstrumentTerm	P5Y
CY2023Q4	us-gaap	Line Of Credit Facility Current Borrowing Capacity LineOfCreditFacilityCurrentBorrowingCapacity	250000000	usd
CY2023Q4	cna	Line Of Credit Facility Additional Borrowing Capacity LineOfCreditFacilityAdditionalBorrowingCapacity	100000000	usd
CY2023Q4	cna	Lineof Credit Facility Numberof Extension Options LineofCreditFacilityNumberofExtensionOptions	2	extensionterm
CY2023	cna	Line Of Credit Facility Extension Term LineOfCreditFacilityExtensionTerm	P1Y
CY2023Q4	us-gaap	Minimum Net Worth Required For Compliance MinimumNetWorthRequiredForCompliance	8700000000	usd
CY2022Q4	us-gaap	Line Of Credit LineOfCredit	0	usd
CY2023Q4	us-gaap	Line Of Credit LineOfCredit	0	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	550000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	0	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	500000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	500000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	1500000000	usd
CY2023Q4	us-gaap	Debt Instrument Unamortized Discount DebtInstrumentUnamortizedDiscount	19000000	usd
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	3031000000	usd
CY2023	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	-27000000	usd
CY2022	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	514000000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	46000000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	49000000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	0	usd
CY2023	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	50000000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-12000000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	262000000	usd
CY2023	cna	Other Comprehensive Income Loss Pensionand Other Postretirement Benefit Plans Settlementsbefore Tax OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansSettlementsbeforeTax	0	usd
CY2022	cna	Other Comprehensive Income Loss Pensionand Other Postretirement Benefit Plans Settlementsbefore Tax OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansSettlementsbeforeTax	0	usd
CY2021	cna	Other Comprehensive Income Loss Pensionand Other Postretirement Benefit Plans Settlementsbefore Tax OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansSettlementsbeforeTax	1000000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	0	usd
CY2022	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	0	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-34000000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-30000000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-46000000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-84000000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-18000000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-309000000	usd
CY2023	cna	Assumptionsusedincalculatingassumedhealthcarecosttrendrate Assumptionsusedincalculatingassumedhealthcarecosttrendrate	0.04
CY2023	cna	Assumptionsusedincalculatingassumedhealthcarecosttrendrate Assumptionsusedincalculatingassumedhealthcarecosttrendrate	0.04
CY2023Q4	cna	Future Capital Call Commitments FutureCapitalCallCommitments	100000000	usd
CY2023	us-gaap	Defined Contribution Plan Maximum Annual Contributions Per Employee Percent DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent	0.50
CY2023	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	1
CY2023	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.06
CY2023	cna	Company Contributionof Eligible Compensation Dependingon Age Percent CompanyContributionofEligibleCompensationDependingonAgePercent	0.05
CY2023	cna	Defined Contribution Plan Employers Matching Contribution Vesting Periodin Years DefinedContributionPlanEmployersMatchingContributionVestingPeriodinYears	P5Y
CY2023	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	82000000	usd
CY2022	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	71000000	usd
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	65000000	usd
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	16000000	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	3600000	shares
CY2023	cna	Measurement Periodof Specific Annual Performance Goalsin Years MeasurementPeriodofSpecificAnnualPerformanceGoalsinYears	P1Y
CY2023	cna	Cliff Vesting Period Following Dateof Grant CliffVestingPeriodFollowingDateofGrant	P2Y
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	38000000	usd
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	36000000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	32000000	usd
CY2023	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	8000000	usd
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CY2023	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y9M18D
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CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	1437605	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	37.06
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	950620	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	38.06
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	478823	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	42.28
CY2023	cna	Performance Based Adjustment Share Based Compensation Equity Instruments Other Than Options PerformanceBasedAdjustmentShareBasedCompensationEquityInstrumentsOtherThanOptions	152399	shares
CY2023	cna	Performance Based Adjustment Share Based Compensation Equity Instruments Other Than Options Weighted Average Grant Date Fair Value PerformanceBasedAdjustmentShareBasedCompensationEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateFairValue	36.87
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CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	41.40
CY2023Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	76000000	usd
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CY2023Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	86000000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	8000000	usd
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$CNA
CNA FINANCIAL CORP Stock $cna

2024 Q1 Form 10-K Financial Statement

#000002117524000007 Filed on February 06, 2024

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Balance Sheet

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$CNA CNA FINANCIAL CORP Stock $cna

2024 Q1 Form 10-K Financial Statement

#000002117524000007 Filed on February 06, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CNA
CNA FINANCIAL CORP Stock $cna