$AFG
AMERICAN FINANCIAL GROUP INC Stock $afg

$afg Overview Financials Valuation SEC Filings Company Website

2020 Q3 Form 10-Q Financial Statement

#000104204620000045 Filed on November 05, 2020

Income Statement

Concept	2020 Q3	2019 Q3
Revenue	$1.556B	$2.123B
YoY Change	-26.71%	5.73%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$169.0M	$123.0M
YoY Change	37.4%	115.79%
% of Gross Profit
Operating Expenses	$1.902B	$1.929B
YoY Change	-1.4%	10.29%
Operating Profit	$40.00M	$177.0M
YoY Change	-77.4%	-27.46%
Interest Expense	$24.00M	$17.00M
YoY Change	41.18%	13.33%
% of Operating Profit	60.0%	9.6%
Other Income/Expense, Net
YoY Change
Pretax Income	$134.0M	$177.0M
YoY Change	-24.29%	-27.46%
Income Tax	-$48.00M	$34.00M
% Of Pretax Income	-35.82%	19.21%
Net Earnings	$164.0M	$147.0M
YoY Change	11.56%	-27.94%
Net Earnings / Revenue	10.54%	6.92%
Basic Earnings Per Share	$1.86	$1.64
Diluted Earnings Per Share	$1.86	$1.62
COMMON SHARES
Basic Shares Outstanding	88.20M shares	90.00M shares
Diluted Shares Outstanding	88.50M shares	91.10M shares

Balance Sheet

Concept	2020 Q3	2019 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$3.747B	$2.693B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$1.185B	$1.187B
YoY Change	-0.17%	-27.31%
LONG-TERM ASSETS
Property, Plant & Equipment	$154.0M	$162.0M
YoY Change	-4.94%
Goodwill	$207.0M	$207.0M
YoY Change	0.0%	4.02%
Intangibles
YoY Change
Long-Term Investments	$1.841B	$1.535B
YoY Change	19.93%	19.08%
Other Assets
YoY Change
Total Long-Term Assets	$71.93B	$67.88B
YoY Change	5.96%	8.51%
TOTAL ASSETS
Total Short-Term Assets	$1.185B	$1.187B
Total Long-Term Assets	$71.93B	$67.88B
Total Assets	$73.11B	$69.07B
YoY Change	5.85%	7.6%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$175.0M	$184.0M
YoY Change	-4.89%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$175.0M	$184.0M
YoY Change	-4.89%
LONG-TERM LIABILITIES
Long-Term Debt	$2.108B	$1.423B
YoY Change	48.14%	9.29%
Other Long-Term Liabilities	$6.597B	$10.04B
YoY Change	-34.31%	-1.89%
Total Long-Term Liabilities	$8.705B	$11.47B
YoY Change	-24.08%	-0.62%
TOTAL LIABILITIES
Total Short-Term Liabilities	$175.0M	$184.0M
Total Long-Term Liabilities	$8.705B	$11.47B
Total Liabilities	$66.77B	$62.75B
YoY Change	6.41%	6.3%
SHAREHOLDERS EQUITY
Retained Earnings
YoY Change
Common Stock	$1.370B	$1.382B
YoY Change	-0.87%	4.7%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$6.340B	$6.321B
YoY Change
Total Liabilities & Shareholders Equity	$73.11B	$69.07B
YoY Change	5.85%	7.6%

Cashflow Statement

Concept	2020 Q3	2019 Q3
OPERATING ACTIVITIES
Net Income	$164.0M	$147.0M
YoY Change	11.56%	-27.94%
Depreciation, Depletion And Amortization	$169.0M	$123.0M
YoY Change	37.4%	115.79%
Cash From Operating Activities	$609.0M	$814.0M
YoY Change	-25.18%	79.3%
INVESTING ACTIVITIES
Capital Expenditures	-$21.00M	-$13.00M
YoY Change	61.54%	-18.75%
Acquisitions
YoY Change
Other Investing Activities	$545.0M	-$713.0M
YoY Change	-176.44%	-18.42%
Cash From Investing Activities	$524.0M	-$726.0M
YoY Change	-172.18%	-18.43%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-84.00M	231.0M
YoY Change	-136.36%	-63.62%
NET CHANGE
Cash From Operating Activities	609.0M	814.0M
Cash From Investing Activities	524.0M	-726.0M
Cash From Financing Activities	-84.00M	231.0M
Net Change In Cash	1.049B	319.0M
YoY Change	228.84%	60.3%
FREE CASH FLOW
Cash From Operating Activities	$609.0M	$814.0M
Capital Expenditures	-$21.00M	-$13.00M
Free Cash Flow	$630.0M	$827.0M
YoY Change	-23.82%	75.96%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Document Period End Date DocumentPeriodEndDate	2020-09-30
	dei	Entity Central Index Key EntityCentralIndexKey	0001042046
	dei	Amendment Flag AmendmentFlag	false
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	afg	Collateralized Loan Obligationsand Other Asset Backed Securities Average Useful Life CollateralizedLoanObligationsandOtherAssetBackedSecuritiesAverageUsefulLife	P4Y
	afg	Mortgage Backed Securities Average Useful Life MortgageBackedSecuritiesAverageUsefulLife	P3Y6M
	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	1-13653
	dei	Entity Registrant Name EntityRegistrantName	AMERICAN FINANCIAL GROUP, INC.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	OH
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	31-1544320
	dei	Entity Address Address Line1 EntityAddressAddressLine1	301 East Fourth Street
	dei	Entity Address City Or Town EntityAddressCityOrTown	Cincinnati
	dei	Entity Address State Or Province EntityAddressStateOrProvince	OH
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	45202
	dei	City Area Code CityAreaCode	513
	dei	Local Phone Number LocalPhoneNumber	579-2121
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
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CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	91100000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	89900000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	90900000	shares
CY2020Q3	us-gaap	Profit Loss ProfitLoss	164000000	USD
CY2019Q3	us-gaap	Profit Loss ProfitLoss	143000000	USD
	us-gaap	Profit Loss ProfitLoss	27000000	USD
	us-gaap	Profit Loss ProfitLoss	678000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	194000000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	107000000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	350000000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	847000000	USD
CY2020Q3	afg	Other Comprehensive Income Loss Reclassification Adjustment For Realized Gains Losses Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForRealizedGainsLossesIncludedInNetIncomeNetOfTax	12000000	USD
CY2019Q3	afg	Other Comprehensive Income Loss Reclassification Adjustment For Realized Gains Losses Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForRealizedGainsLossesIncludedInNetIncomeNetOfTax	-1000000	USD
	afg	Other Comprehensive Income Loss Reclassification Adjustment For Realized Gains Losses Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForRealizedGainsLossesIncludedInNetIncomeNetOfTax	0	USD
	afg	Other Comprehensive Income Loss Reclassification Adjustment For Realized Gains Losses Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForRealizedGainsLossesIncludedInNetIncomeNetOfTax	10000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	182000000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	108000000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	350000000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	837000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	-6000000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	7000000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	24000000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	36000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	0	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-7000000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-6000000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-3000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-1000000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-1000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	176000000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	109000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	368000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	871000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	340000000	USD
CY2019Q3	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	252000000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	395000000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	1549000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	0	USD
CY2019Q3	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-3000000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-11000000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-6000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	340000000	USD
CY2019Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	255000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	406000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1555000000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6126000000	USD
CY2020Q2	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
CY2020Q3	us-gaap	Net Income Loss Including Portion Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest	164000000	USD
CY2020Q3	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	0	USD
CY2020Q3	afg	Other Comprehensive Income Loss Netof Taxincluding Portion Attributableto Noncontrolling Interest OtherComprehensiveIncomeLossNetofTaxincludingPortionAttributabletoNoncontrollingInterest	176000000	USD
CY2020Q3	afg	Other Comprehensive Income Loss Netof Tax Attributableto Redeemable Noncontrolling Interests OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterests	0	USD
CY2020Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2020Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	39000000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1000000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	2000000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1000000	USD
CY2020Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	5000000	USD
CY2020Q3	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	96000000	USD
CY2020Q3	afg	Stock Repurchased Shares Exchanged In Stock Compensation Plans Value StockRepurchasedSharesExchangedInStockCompensationPlansValue	0	USD
CY2020Q3	us-gaap	Stockholders Equity Other StockholdersEquityOther	0	USD
CY2020Q3	us-gaap	Temporary Equity Other Changes TemporaryEquityOtherChanges	0	USD
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6340000000	USD
CY2020Q3	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
CY2019Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6090000000	USD
CY2019Q2	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
CY2019Q3	us-gaap	Net Income Loss Including Portion Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest	147000000	USD
CY2019Q3	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	4000000	USD
CY2019Q3	afg	Other Comprehensive Income Loss Netof Taxincluding Portion Attributableto Noncontrolling Interest OtherComprehensiveIncomeLossNetofTaxincludingPortionAttributabletoNoncontrollingInterest	108000000	USD
CY2019Q3	afg	Other Comprehensive Income Loss Netof Tax Attributableto Redeemable Noncontrolling Interests OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterests	1000000	USD
CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	36000000	USD
CY2019Q3	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	8000000	USD
CY2019Q3	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	2000000	USD
CY2019Q3	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	0	USD
CY2019Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	5000000	USD
CY2019Q3	afg	Stock Repurchased Shares Exchanged In Stock Compensation Plans Value StockRepurchasedSharesExchangedInStockCompensationPlansValue	0	USD
CY2019Q3	us-gaap	Stockholders Equity Other StockholdersEquityOther	3000000	USD
CY2019Q3	us-gaap	Temporary Equity Other Changes TemporaryEquityOtherChanges	3000000	USD
CY2019Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6321000000	USD
CY2019Q3	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6269000000	USD
CY2019Q4	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
	us-gaap	Net Income Loss Including Portion Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest	40000000	USD
	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	13000000	USD
	afg	Other Comprehensive Income Loss Netof Taxincluding Portion Attributableto Noncontrolling Interest OtherComprehensiveIncomeLossNetofTaxincludingPortionAttributabletoNoncontrollingInterest	366000000	USD
	afg	Other Comprehensive Income Loss Netof Tax Attributableto Redeemable Noncontrolling Interests OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterests	2000000	USD
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.35
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	120000000	USD
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	10000000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	7000000	USD
	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1000000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	15000000	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	233000000	USD
	afg	Stock Repurchased Shares Exchanged In Stock Compensation Plans Value StockRepurchasedSharesExchangedInStockCompensationPlansValue	11000000	USD
	us-gaap	Stockholders Equity Other StockholdersEquityOther	11000000	USD
	us-gaap	Temporary Equity Other Changes TemporaryEquityOtherChanges	11000000	USD
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6340000000	USD
CY2020Q3	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4972000000	USD
CY2018Q4	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
	us-gaap	Net Income Loss Including Portion Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest	686000000	USD
	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	8000000	USD
	afg	Other Comprehensive Income Loss Netof Taxincluding Portion Attributableto Noncontrolling Interest OtherComprehensiveIncomeLossNetofTaxincludingPortionAttributabletoNoncontrollingInterest	869000000	USD
	afg	Other Comprehensive Income Loss Netof Tax Attributableto Redeemable Noncontrolling Interests OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterests	2000000	USD
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.70
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	242000000	USD
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	25000000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	6000000	USD
	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1000000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	17000000	USD
	afg	Stock Repurchased Shares Exchanged In Stock Compensation Plans Value StockRepurchasedSharesExchangedInStockCompensationPlansValue	5000000	USD
	us-gaap	Stockholders Equity Other StockholdersEquityOther	8000000	USD
	us-gaap	Temporary Equity Other Changes TemporaryEquityOtherChanges	6000000	USD
CY2019Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6321000000	USD
CY2019Q3	us-gaap	Temporary Equity Carrying Amount Including Portion Attributable To Noncontrolling Interests TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests	0	USD
	us-gaap	Profit Loss ProfitLoss	27000000	USD
	us-gaap	Profit Loss ProfitLoss	678000000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	248000000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	195000000	USD
	afg	Annuity Benefits AnnuityBenefits	905000000	USD
	afg	Annuity Benefits AnnuityBenefits	900000000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-332000000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	223000000	USD
	us-gaap	Proceeds From Payments For Trading Securities ProceedsFromPaymentsForTradingSecurities	18000000	USD
	us-gaap	Proceeds From Payments For Trading Securities ProceedsFromPaymentsForTradingSecurities	-2000000	USD
	afg	Deferred Annuity And Life Policy Acquisition Costs DeferredAnnuityAndLifePolicyAcquisitionCosts	112000000	USD
	afg	Deferred Annuity And Life Policy Acquisition Costs DeferredAnnuityAndLifePolicyAcquisitionCosts	163000000	USD
	afg	Increase Decreasein Reinsuranceand Other Receivables IncreaseDecreaseinReinsuranceandOtherReceivables	597000000	USD
	afg	Increase Decreasein Reinsuranceand Other Receivables IncreaseDecreaseinReinsuranceandOtherReceivables	330000000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-120000000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	281000000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	702000000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	475000000	USD
	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	163000000	USD
	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	115000000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-220000000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	417000000	USD
	afg	Changein Managed Investment Entities Assets And Liabilities ChangeinManagedInvestmentEntitiesAssetsAndLiabilities	-99000000	USD
	afg	Changein Managed Investment Entities Assets And Liabilities ChangeinManagedInvestmentEntitiesAssetsAndLiabilities	2000000	USD
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	11000000	USD
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-88000000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1696000000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1691000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	7817000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	5533000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	354000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	161000000	USD
	us-gaap	Payments To Acquire Mortgage Notes Receivable PaymentsToAcquireMortgageNotesReceivable	197000000	USD
	us-gaap	Payments To Acquire Mortgage Notes Receivable PaymentsToAcquireMortgageNotesReceivable	181000000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	699000000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	658000000	USD
	afg	Purchases Of Real Estate Property And Equipment PurchasesOfRealEstatePropertyAndEquipment	41000000	USD
	afg	Purchases Of Real Estate Property And Equipment PurchasesOfRealEstatePropertyAndEquipment	33000000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	4114000000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	3411000000	USD
	us-gaap	Proceeds From Sale And Collection Of Mortgage Notes Receivable ProceedsFromSaleAndCollectionOfMortgageNotesReceivable	48000000	USD
	us-gaap	Proceeds From Sale And Collection Of Mortgage Notes Receivable ProceedsFromSaleAndCollectionOfMortgageNotesReceivable	76000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	3123000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	569000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	421000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	223000000	USD
	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	673000000	USD
	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	486000000	USD
	afg	Proceeds From Sales Of Real Estate Property And Equipment ProceedsFromSalesOfRealEstatePropertyAndEquipment	7000000	USD
	afg	Proceeds From Sales Of Real Estate Property And Equipment ProceedsFromSalesOfRealEstatePropertyAndEquipment	3000000	USD
	afg	Purchases Of Investments By Managed Investment Entities PurchasesOfInvestmentsByManagedInvestmentEntities	878000000	USD
	afg	Purchases Of Investments By Managed Investment Entities PurchasesOfInvestmentsByManagedInvestmentEntities	1062000000	USD
	afg	Proceeds From Sales And Redemptions Of Investments By Managed Investment Entities ProceedsFromSalesAndRedemptionsOfInvestmentsByManagedInvestmentEntities	818000000	USD
	afg	Proceeds From Sales And Redemptions Of Investments By Managed Investment Entities ProceedsFromSalesAndRedemptionsOfInvestmentsByManagedInvestmentEntities	1081000000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-10000000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-1000000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-772000000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1778000000	USD
	us-gaap	Proceeds From Annuities And Investment Certificates ProceedsFromAnnuitiesAndInvestmentCertificates	2968000000	USD
	us-gaap	Proceeds From Annuities And Investment Certificates ProceedsFromAnnuitiesAndInvestmentCertificates	3821000000	USD
	us-gaap	Repayments Of Annuities And Investment Certificates RepaymentsOfAnnuitiesAndInvestmentCertificates	2506000000	USD
	us-gaap	Repayments Of Annuities And Investment Certificates RepaymentsOfAnnuitiesAndInvestmentCertificates	2502000000	USD
	afg	Annuity Receipts Ceded AnnuityReceiptsCeded	246000000	USD
	afg	Annuity Receipts Ceded AnnuityReceiptsCeded	0	USD
	afg	Net Transfers From To Separate Accounts NetTransfersFromToSeparateAccounts	44000000	USD
	afg	Net Transfers From To Separate Accounts NetTransfersFromToSeparateAccounts	45000000	USD
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	635000000	USD
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	121000000	USD
	afg	Proceeds From Issuance Of Managed Investment Entities ProceedsFromIssuanceOfManagedInvestmentEntities	30000000	USD
	afg	Proceeds From Issuance Of Managed Investment Entities ProceedsFromIssuanceOfManagedInvestmentEntities	0	USD
	afg	Retirement Of Managed Investment Entities Liabilities RetirementOfManagedInvestmentEntitiesLiabilities	79000000	USD
	afg	Retirement Of Managed Investment Entities Liabilities RetirementOfManagedInvestmentEntitiesLiabilities	8000000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	15000000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	29000000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	233000000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	119000000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	241000000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	509000000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1265000000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	1433000000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	1178000000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2314000000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1515000000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	3747000000	USD
CY2019Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2693000000	USD
	us-gaap	Basis Of Accounting BasisOfAccounting	<div><span style="color:#003366;font-family:'Arial',sans-serif;font-size:11pt;font-weight:700;line-height:120%">Basis of Presentation</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9.5pt;font-weight:700;line-height:120%"> </span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9.5pt;font-weight:400;line-height:120%">The accompanying consolidated financial statements for American Financial Group, Inc. and its subsidiaries (“AFG”) are unaudited; however, management believes that all adjustments (consisting only of normal recurring accruals unless otherwise disclosed herein) necessary for fair presentation have been made. The results of operations for interim periods are not necessarily indicative of results to be expected for the year. The financial statements have been prepared in accordance with the instructions to Form 10-Q and, therefore, do not include all information and footnotes necessary to be in conformity with U.S. generally accepted accounting principles (“GAAP”).</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9.5pt;font-weight:400;line-height:120%">Certain reclassifications have been made to prior periods to conform to the current year’s presentation. All significant intercompany balances and transactions have been eliminated. The results of operations of companies since their formation or acquisition are included in the consolidated financial statements. Events or transactions occurring subsequent to September 30, 2020, and prior to the filing of this Form 10-Q, have been evaluated for potential recognition or disclosure herein.</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9.5pt;font-weight:400;line-height:120%">The preparation of the financial statements requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Changes in circumstances could cause actual results to differ materially from those estimates.</span></div>
	us-gaap	Revenue Recognition Deferred Revenue RevenueRecognitionDeferredRevenue	<span style="color:#003366;font-family:'Arial',sans-serif;font-size:11pt;font-weight:700;line-height:120%">Unearned Revenue</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9.5pt;font-weight:400;line-height:120%"> Certain upfront policy charges on annuities are deferred as unearned revenue (included in other liabilities) and recognized in net earnings (included in other income) using the same assumptions and estimated gross profits used to amortize DPAC.</span>
CY2020Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	175000000	USD
CY2020Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	154000000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	180000000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	158000000	USD
CY2020Q3	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	300000	shares
CY2019Q3	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1100000	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	500000	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1200000	shares
CY2020Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2019Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	afg	Maturity Period Of Short Term Investment Maximum MaturityPeriodOfShortTermInvestmentMaximum	P3M
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2020Q3	afg	Revenues Before Realized Gains Losses RevenuesBeforeRealizedGainsLosses	2045000000	USD
CY2019Q3	afg	Revenues Before Realized Gains Losses RevenuesBeforeRealizedGainsLosses	2141000000	USD
	afg	Revenues Before Realized Gains Losses RevenuesBeforeRealizedGainsLosses	5618000000	USD
	afg	Revenues Before Realized Gains Losses RevenuesBeforeRealizedGainsLosses	5885000000	USD
CY2020Q3	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	45000000	USD
CY2019Q3	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	-18000000	USD
	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	-302000000	USD
	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	222000000	USD
CY2020Q3	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	-30000000	USD
CY2019Q3	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	0	USD
	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	-30000000	USD
	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	0	USD
CY2020Q3	us-gaap	Revenues Revenues	2060000000	USD
CY2019Q3	us-gaap	Revenues Revenues	2123000000	USD
	us-gaap	Revenues Revenues	5286000000	USD
	us-gaap	Revenues Revenues	6107000000	USD
CY2020Q3	afg	Operating Income Loss Before Realized Gains Losses And Income Taxes OperatingIncomeLossBeforeRealizedGainsLossesAndIncomeTaxes	119000000	USD
CY2019Q3	afg	Operating Income Loss Before Realized Gains Losses And Income Taxes OperatingIncomeLossBeforeRealizedGainsLossesAndIncomeTaxes	195000000	USD
	afg	Operating Income Loss Before Realized Gains Losses And Income Taxes OperatingIncomeLossBeforeRealizedGainsLossesAndIncomeTaxes	296000000	USD
	afg	Operating Income Loss Before Realized Gains Losses And Income Taxes OperatingIncomeLossBeforeRealizedGainsLossesAndIncomeTaxes	627000000	USD
CY2020Q3	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	45000000	USD
CY2019Q3	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	-18000000	USD
	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	-302000000	USD
	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	222000000	USD
CY2020Q3	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	-30000000	USD
CY2019Q3	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	0	USD
	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	-30000000	USD
	afg	Realized Gains Losses On Disposal Of Subsidiaries RealizedGainsLossesOnDisposalOfSubsidiaries	0	USD
CY2020Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	134000000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	177000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	-36000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	849000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	849000000	USD
	afg	Number Of Internal Investment Professionals NumberOfInternalInvestmentProfessionals	20	professional
CY2020Q3	afg	Variable Annuity Assets Fair Value Disclosure VariableAnnuityAssetsFairValueDisclosure	603000000	USD
CY2020Q3	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	56022000000	USD
CY2020Q3	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	8207000000	USD
CY2019Q4	afg	Variable Annuity Assets Fair Value Disclosure VariableAnnuityAssetsFairValueDisclosure	628000000	USD
CY2019Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	54893000000	USD
CY2019Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	8311000000	USD
	afg	Level Three Asset As Percentage Of Asset Measured At Fair Value LevelThreeAssetAsPercentageOfAssetMeasuredAtFairValue	0.07
	afg	Percentage Of Level Three Assets That Were Priced Using Non Binding Broker Quotes PercentageOfLevelThreeAssetsThatWerePricedUsingNonBindingBrokerQuotes	0.38
	afg	Level Three Assets That Were Priced Using Non Binding Broker Quotes LevelThreeAssetsThatWerePricedUsingNonBindingBrokerQuotes	1460000000	USD
CY2020Q3	afg	Percentof Spreads Usedin Third Party Pricing Model PercentofSpreadsUsedinThirdPartyPricingModel	0.80
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3840000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-13000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	23000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	104000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	159000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	247000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	237000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3805000000	USD
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3675000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	5000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Other Comprehensive Income FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome	0	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	56000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	79000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3657000000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3106000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-8000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	23000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	399000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	90000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	88000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	2000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3516000000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3541000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-70000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Other Comprehensive Income FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome	0	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	63000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	65000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3469000000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3841000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-58000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	47000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	569000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	432000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	598000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	760000000	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3805000000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3730000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-41000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Other Comprehensive Income FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	180000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	212000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	USD
CY2020Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3657000000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3521000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	87000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	1172000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	488000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	145000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	921000000	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	3516000000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	2720000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	643000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Other Comprehensive Income FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	276000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	170000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3469000000	USD
CY2020Q3	afg	Life Contingent Annuities LifeContingentAnnuities	850000000	USD
CY2019Q4	afg	Life Contingent Annuities LifeContingentAnnuities	247000000	USD
	afg	Percentage Based On Unrealized Loss Of Available For Sale Fixed Maturities That Are In Unrealized Loss Position And Rated Investment Grade PercentageBasedOnUnrealizedLossOfAvailableForSaleFixedMaturitiesThatAreInUnrealizedLossPositionAndRatedInvestmentGrade	0.77
	afg	Percentage Based On Fair Value Of Available For Sale Fixed Maturities That Are In Unrealized Loss Position And Rated Investment Grade PercentageBasedOnFairValueOfAvailableForSaleFixedMaturitiesThatAreInUnrealizedLossPositionAndRatedInvestmentGrade	0.84
CY2020Q2	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	61000000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Purchased With Credit Deterioration Increase DebtSecuritiesAvailableForSaleAllowanceForCreditLossPurchasedWithCreditDeteriorationIncrease	0	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded	0	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not To Sell Before Recovery Credit Loss Previously Recorded Expense Reversal DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal	-3000000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Securities Sold DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold	4000000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	54000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Purchased With Credit Deterioration Increase DebtSecuritiesAvailableForSaleAllowanceForCreditLossPurchasedWithCreditDeteriorationIncrease	1000000	USD
	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded	67000000	USD
	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not To Sell Before Recovery Credit Loss Previously Recorded Expense Reversal DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal	-10000000	USD
	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Securities Sold DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold	4000000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	54000000	USD
CY2020Q3	afg	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Pretax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentPretax	1534000000	USD
CY2020Q3	afg	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Deferred Tax And Non Controlling Interest AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentDeferredTaxAndNonControllingInterest	322000000	USD
CY2020Q3	us-gaap	Net Investment Income NetInvestmentIncome	572000000	USD
CY2019Q3	us-gaap	Net Investment Income NetInvestmentIncome	588000000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	1212000000	USD
CY2019Q4	afg	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Pretax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentPretax	1091000000	USD
CY2019Q4	afg	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Deferred Tax And Non Controlling Interest AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentDeferredTaxAndNonControllingInterest	229000000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	862000000	USD
CY2020Q3	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	66000000	USD
CY2019Q3	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	43000000	USD
	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	37000000	USD
	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	109000000	USD
CY2020Q3	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	578000000	USD
CY2019Q3	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	593000000	USD
	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	1601000000	USD
	us-gaap	Gross Investment Income Operating GrossInvestmentIncomeOperating	1727000000	USD
CY2020Q3	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	6000000	USD
CY2019Q3	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	5000000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	17000000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	17000000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1584000000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1710000000	USD
CY2020Q3	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	342000000	USD
CY2019Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	577000000	USD
CY2020Q2	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	818000000	USD
CY2020Q3	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Additions DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAdditions	175000000	USD
CY2020Q3	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization1 DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortization1	212000000	USD
CY2020Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Effect Of Adjustments To Estimated Gross Profit DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseEffectOfAdjustmentsToEstimatedGrossProfit	114000000	USD
CY2020Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Net Investment Gains Losses DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseNetInvestmentGainsLosses	2000000	USD
CY2020Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Foreign Currency Translation Adjustment DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsForeignCurrencyTranslationAdjustment	1000000	USD
CY2020Q3	afg	Deferred Policy Acquisition Costsand Present Valueof Future Profits Changein Unrealized Investment Gain Loss DeferredPolicyAcquisitionCostsandPresentValueofFutureProfitsChangeinUnrealizedInvestmentGainLoss	-169000000	USD
CY2020Q3	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	497000000	USD
CY2019Q2	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	1203000000	USD
CY2019Q3	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Additions DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAdditions	232000000	USD
CY2019Q3	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization1 DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortization1	227000000	USD
CY2019Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Effect Of Adjustments To Estimated Gross Profit DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseEffectOfAdjustmentsToEstimatedGrossProfit	77000000	USD
CY2019Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Net Investment Gains Losses DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseNetInvestmentGainsLosses	-3000000	USD
CY2019Q3	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Foreign Currency Translation Adjustment DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsForeignCurrencyTranslationAdjustment	-1000000	USD
CY2019Q3	afg	Deferred Policy Acquisition Costsand Present Valueof Future Profits Changein Unrealized Investment Gain Loss DeferredPolicyAcquisitionCostsandPresentValueofFutureProfitsChangeinUnrealizedInvestmentGainLoss	-169000000	USD
CY2019Q3	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	964000000	USD
CY2019Q4	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	1037000000	USD
	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Additions DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAdditions	561000000	USD
	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization1 DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortization1	597000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Effect Of Adjustments To Estimated Gross Profit DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseEffectOfAdjustmentsToEstimatedGrossProfit	114000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Net Investment Gains Losses DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseNetInvestmentGainsLosses	-7000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Foreign Currency Translation Adjustment DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsForeignCurrencyTranslationAdjustment	-1000000	USD
	afg	Deferred Policy Acquisition Costsand Present Valueof Future Profits Changein Unrealized Investment Gain Loss DeferredPolicyAcquisitionCostsandPresentValueofFutureProfitsChangeinUnrealizedInvestmentGainLoss	-396000000	USD
CY2020Q3	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	497000000	USD
CY2018Q4	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	1682000000	USD
	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Additions DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAdditions	734000000	USD
	us-gaap	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization1 DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortization1	622000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Effect Of Adjustments To Estimated Gross Profit DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseEffectOfAdjustmentsToEstimatedGrossProfit	77000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Amortization Expense Net Investment Gains Losses DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsAmortizationExpenseNetInvestmentGainsLosses	-6000000	USD
	afg	Deferred Policy Acquisition Costs And Present Value Of Future Profits Foreign Currency Translation Adjustment DeferredPolicyAcquisitionCostsAndPresentValueOfFutureProfitsForeignCurrencyTranslationAdjustment	-1000000	USD
	afg	Deferred Policy Acquisition Costsand Present Valueof Future Profits Changein Unrealized Investment Gain Loss DeferredPolicyAcquisitionCostsandPresentValueofFutureProfitsChangeinUnrealizedInvestmentGainLoss	-758000000	USD
CY2019Q3	afg	Gain Loss On Change In Fair Value Of Liabilities Of Variable Interest Entities GainLossOnChangeInFairValueOfLiabilitiesOfVariableInterestEntities	4000000	USD
	afg	Gain Loss On Change In Fair Value Of Liabilities Of Variable Interest Entities GainLossOnChangeInFairValueOfLiabilitiesOfVariableInterestEntities	137000000	USD
CY2019Q3	us-gaap	Deferred Policy Acquisition Costs And Value Of Business Acquired DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired	964000000	USD
CY2020Q3	afg	Accumulated Amortization Of Present Value Of Future Profits AccumulatedAmortizationOfPresentValueOfFutureProfits	158000000	USD
CY2019Q4	afg	Accumulated Amortization Of Present Value Of Future Profits AccumulatedAmortizationOfPresentValueOfFutureProfits	154000000	USD
	afg	Percentage Of Investment Of Most Subordinate Debt Tranche Of Variable Interest Entity Minimum PercentageOfInvestmentOfMostSubordinateDebtTrancheOfVariableInterestEntityMinimum	0.150
	afg	Percentage Of Investment Of Most Subordinate Debt Tranche Of Variable Interest Entity Maximum PercentageOfInvestmentOfMostSubordinateDebtTrancheOfVariableInterestEntityMaximum	1.000
	afg	Number Of Collateralized Loan Obligation Entities NumberOfCollateralizedLoanObligationEntities	11	collateralizedloanobligation
	afg	Face Amount Of Managed Investment Entities Liabilities Purchased By Subsidiaries After Issuance Date FaceAmountOfManagedInvestmentEntitiesLiabilitiesPurchasedBySubsidiariesAfterIssuanceDate	57000000	USD
	afg	Amount Paid By Subsidiaries To Purchase Managed Investment Entities Liabilities After Issuance Date. AmountPaidBySubsidiariesToPurchaseManagedInvestmentEntitiesLiabilitiesAfterIssuanceDate.	39000000	USD
CY2020Q3	afg	Gain Loss On Change In Fair Value Of Assets Of Variable Interest Entities GainLossOnChangeInFairValueOfAssetsOfVariableInterestEntities	132000000	USD
CY2019Q3	afg	Gain Loss On Change In Fair Value Of Assets Of Variable Interest Entities GainLossOnChangeInFairValueOfAssetsOfVariableInterestEntities	-18000000	USD
	afg	Gain Loss On Change In Fair Value Of Assets Of Variable Interest Entities GainLossOnChangeInFairValueOfAssetsOfVariableInterestEntities	-184000000	USD
	afg	Gain Loss On Change In Fair Value Of Assets Of Variable Interest Entities GainLossOnChangeInFairValueOfAssetsOfVariableInterestEntities	69000000	USD
CY2020Q3	afg	Gain Loss On Change In Fair Value Of Liabilities Of Variable Interest Entities GainLossOnChangeInFairValueOfLiabilitiesOfVariableInterestEntities	-131000000	USD
	afg	Gain Loss On Change In Fair Value Of Liabilities Of Variable Interest Entities GainLossOnChangeInFairValueOfLiabilitiesOfVariableInterestEntities	-85000000	USD
CY2020Q3	afg	Management Fees Paid By Variable Interest Entities ManagementFeesPaidByVariableInterestEntities	3000000	USD
CY2019Q3	afg	Management Fees Paid By Variable Interest Entities ManagementFeesPaidByVariableInterestEntities	4000000	USD
	afg	Management Fees Paid By Variable Interest Entities ManagementFeesPaidByVariableInterestEntities	11000000	USD
	afg	Management Fees Paid By Variable Interest Entities ManagementFeesPaidByVariableInterestEntities	11000000	USD
CY2020Q3	afg	Earnings Losses Of Variable Interest Entities Attributable To Shareholders EarningsLossesOfVariableInterestEntitiesAttributableToShareholders	13000000	USD
CY2019Q3	afg	Earnings Losses Of Variable Interest Entities Attributable To Shareholders EarningsLossesOfVariableInterestEntitiesAttributableToShareholders	-5000000	USD
	afg	Earnings Losses Of Variable Interest Entities Attributable To Shareholders EarningsLossesOfVariableInterestEntitiesAttributableToShareholders	-21000000	USD
	afg	Earnings Losses Of Variable Interest Entities Attributable To Shareholders EarningsLossesOfVariableInterestEntitiesAttributableToShareholders	11000000	USD
CY2020Q3	afg	Difference Between Aggregate Unpaid Principal Balance And Fair Value Of Variable Interest Entity Investments DifferenceBetweenAggregateUnpaidPrincipalBalanceAndFairValueOfVariableInterestEntityInvestments	276000000	USD
CY2019Q4	afg	Difference Between Aggregate Unpaid Principal Balance And Fair Value Of Variable Interest Entity Investments DifferenceBetweenAggregateUnpaidPrincipalBalanceAndFairValueOfVariableInterestEntityInvestments	146000000	USD
CY2020Q3	afg	Difference Between Aggregate Unpaid Principal Balance And Fair Value Of Variable Interest Entity Debt DifferenceBetweenAggregateUnpaidPrincipalBalanceAndFairValueOfVariableInterestEntityDebt	248000000	USD
CY2019Q4	afg	Difference Between Aggregate Unpaid Principal Balance And Fair Value Of Variable Interest Entity Debt DifferenceBetweenAggregateUnpaidPrincipalBalanceAndFairValueOfVariableInterestEntityDebt	129000000	USD
CY2020Q3	afg	Carrying Amount Of Variable Interest Entity Loans In Default CarryingAmountOfVariableInterestEntityLoansInDefault	26000000	USD
CY2019Q4	afg	Carrying Amount Of Variable Interest Entity Loans In Default CarryingAmountOfVariableInterestEntityLoansInDefault	10000000	USD
CY2020Q3	afg	Aggregateunpaidprincipalbalanceofvariableinterestentityloansindefault Aggregateunpaidprincipalbalanceofvariableinterestentityloansindefault	55000000	USD
CY2019Q4	afg	Aggregateunpaidprincipalbalanceofvariableinterestentityloansindefault Aggregateunpaidprincipalbalanceofvariableinterestentityloansindefault	25000000	USD
	us-gaap	Goodwill Period Increase Decrease GoodwillPeriodIncreaseDecrease	0	USD
CY2020Q3	us-gaap	Goodwill Goodwill	207000000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	34000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	43000000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	59000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	50000000	USD
CY2019Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3000000	USD
CY2020Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3000000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	9000000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	9000000	USD
CY2020Q3	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	2143000000	USD
CY2020Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	35000000	USD
CY2020Q3	us-gaap	Long Term Debt LongTermDebt	2108000000	USD
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	1493000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	20000000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	1473000000	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal Remainder Of Fiscal Year LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	0	USD
CY2020Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	5000000	USD
CY2019Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	5000000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	15000000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17000000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	134000000	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	177000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-36000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	849000000	USD
CY2020Q3	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	28000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019Q3	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	37000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-8000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	178000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020Q3	us-gaap	Income Tax Reconciliation Disposition Of Business IncomeTaxReconciliationDispositionOfBusiness	-73000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Disposition Of Business EffectiveIncomeTaxRateReconciliationDispositionOfBusiness	-0.54
CY2019Q3	us-gaap	Income Tax Reconciliation Disposition Of Business IncomeTaxReconciliationDispositionOfBusiness	0	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Disposition Of Business EffectiveIncomeTaxRateReconciliationDispositionOfBusiness	0
	us-gaap	Income Tax Reconciliation Disposition Of Business IncomeTaxReconciliationDispositionOfBusiness	-73000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Disposition Of Business EffectiveIncomeTaxRateReconciliationDispositionOfBusiness	2.03
	us-gaap	Income Tax Reconciliation Disposition Of Business IncomeTaxReconciliationDispositionOfBusiness	0	USD
	us-gaap	Effective Income Tax Rate Reconciliation Disposition Of Business EffectiveIncomeTaxRateReconciliationDispositionOfBusiness	0
CY2020Q3	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	3000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.02
CY2019Q3	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	4000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.02
	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	9000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.25
	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	11000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.01
CY2020Q3	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	0	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0
CY2019Q3	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-2000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.01
	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-4000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.11
	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-6000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.01
CY2020Q3	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	1000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Deductions Dividends EffectiveIncomeTaxRateReconciliationDeductionsDividends	0.01
CY2019Q3	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	1000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Deductions Dividends EffectiveIncomeTaxRateReconciliationDeductionsDividends	0.01
	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	2000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Deductions Dividends EffectiveIncomeTaxRateReconciliationDeductionsDividends	-0.06
	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	3000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Deductions Dividends EffectiveIncomeTaxRateReconciliationDeductionsDividends	0
CY2020Q3	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-1000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.01
CY2019Q3	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-3000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.02
	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-1000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.03
	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-3000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0
CY2020Q3	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	1000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0.01
CY2019Q3	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0
	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	1000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	-0.03
	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	1000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0
CY2020Q3	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	20000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.15
CY2019Q3	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	4000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.02
	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	31000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.86
	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	7000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.01
CY2020Q3	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	2000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.01
CY2019Q3	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	2000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.01
	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	4000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	-0.11
	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	6000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.01
CY2020Q3	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-4000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.03
CY2019Q3	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	0	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0
	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-3000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.08
	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	0	USD
	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0
CY2020Q3	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	3000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.03
CY2019Q3	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	1000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.01
	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	3000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.08
	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	4000000	USD
	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.01
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-30000000	USD
CY2020Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.22
CY2019Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34000000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.19
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-63000000	USD
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	1.75
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171000000	USD
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.20
CY2020Q3	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	23000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	2359000000	USD
	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	The following table provides an analysis of changes in the liability for losses and loss adjustment expenses during the first nine months of 2020 and 2019 (in millions):<table style="border-collapse:collapse;display:inline-table;vertical-align:top;width:100.000%"><tr><td style="width:1.0%"/><td style="width:71.707%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.204%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.384%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.205%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Nine months ended September 30,</span></td></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2020</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2019</span></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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Balance at beginning of year</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">10,232 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">9,741 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Less reinsurance recoverables, net of allowance</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">3,024 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,942 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Net liability at beginning of year</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">7,208 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">6,799 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Provision for losses and LAE occurring in the current period</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,560 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,457 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Net increase (decrease) in the provision for claims of prior years:</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 12.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Special A&E charges</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">47 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">18 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 12.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(166)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(116)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 24.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Total losses and LAE incurred</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,441 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,359 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Payments for losses and LAE of:</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 11.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Current year</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(592)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(731)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 11.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Prior years</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(1,406)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(1,408)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 24.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Total 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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(1,998)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(2,139)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Foreign currency translation 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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(11)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">(5)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Net liability at end of period</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">7,640 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">7,014 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Add back reinsurance recoverables, net of allowance</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">3,114 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">2,833 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Gross unpaid losses and LAE included in the balance sheet at end of period</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">10,754 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">$</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:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">9,847 </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"/></tr></table>
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense Property Casualty Liability LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability	10232000000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense Property Casualty Liability LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability	9741000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	3024000000	USD
CY2018Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	2942000000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7208000000	USD
CY2018Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	6799000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	2560000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	2457000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-166000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-116000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	2441000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	592000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	731000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	1406000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	1408000000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	1998000000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	2139000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	-11000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	-5000000	USD
CY2020Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7640000000	USD
CY2019Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7014000000	USD
CY2020Q3	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	3114000000	USD
CY2019Q3	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	2833000000	USD
CY2020Q3	us-gaap	Liability For Claims And Claims Adjustment Expense Property Casualty Liability LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability	10754000000	USD
CY2019Q3	us-gaap	Liability For Claims And Claims Adjustment Expense Property Casualty Liability LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability	9847000000	USD
CY2020Q2	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	13000000	USD
CY2020Q2	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	10000000	USD
CY2020Q3	us-gaap	Reinsurance Recoverable Credit Loss Expense Reversal ReinsuranceRecoverableCreditLossExpenseReversal	1000000	USD
CY2020Q3	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	1000000	USD
CY2020Q3	us-gaap	Reinsurance Loss On Uncollectible Accounts In Period Amount ReinsuranceLossOnUncollectibleAccountsInPeriodAmount	0	USD
CY2020Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	0	USD
CY2020Q3	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	14000000	USD
CY2020Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	11000000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	18000000	USD
CY2019Q4	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	13000000	USD
CY2020Q1	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	6000000	USD
CY2020Q1	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	3000000	USD
	us-gaap	Reinsurance Recoverable Credit Loss Expense Reversal ReinsuranceRecoverableCreditLossExpenseReversal	2000000	USD
	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	1000000	USD
	us-gaap	Reinsurance Loss On Uncollectible Accounts In Period Amount ReinsuranceLossOnUncollectibleAccountsInPeriodAmount	0	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	0	USD
CY2020Q3	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	14000000	USD
CY2020Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	11000000	USD

Files In Submission

Name	View Source	Status
0001042046-20-000045-index-headers.html	Edgar Link	pending
0001042046-20-000045-index.html	Edgar Link	pending
0001042046-20-000045.txt	Edgar Link	pending
0001042046-20-000045-xbrl.zip	Edgar Link	pending
afg-20200930.htm	Edgar Link	pending
afg-20200930.xsd	Edgar Link	pending
afg-20200930_cal.xml	Edgar Link	unprocessable
afg-20200930_def.xml	Edgar Link	unprocessable
afg-20200930_g1.jpg	Edgar Link	pending
afg-20200930_htm.xml	Edgar Link	completed
afg-20200930_lab.xml	Edgar Link	unprocessable
afg-20200930_pre.xml	Edgar Link	unprocessable
afg-2020930xex31a.htm	Edgar Link	pending
afg-2020930xex31b.htm	Edgar Link	pending
afg-2020930xex31c.htm	Edgar Link	pending
afg-2020930xex32.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
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R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

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$AFG
AMERICAN FINANCIAL GROUP INC Stock $afg

2020 Q3 Form 10-Q Financial Statement

#000104204620000045 Filed on November 05, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AFG AMERICAN FINANCIAL GROUP INC Stock $afg

2020 Q3 Form 10-Q Financial Statement

#000104204620000045 Filed on November 05, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AFG
AMERICAN FINANCIAL GROUP INC Stock $afg