Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Face (par) amount of the original debt instrument that was repurchased.

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No definition available.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Description of interest rate for borrowing under credit facility. Includes, but is not limited to, terms and method for determining interest rate.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Long-Term Debt - Narrative (Details) - USD ($)	12 Months Ended
Long-Term Debt - Narrative (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Nov. 15, 2020	Sep. 30, 2020	May 29, 2020	Apr. 02, 2020	Mar. 31, 2019
Long-term Debt, Fiscal Year Maturity [Abstract]
Scheduled principal payments on debt in next year	$ 0
Scheduled principal payments on debt in year two	0
Scheduled principal payments on debt in year three	0
Scheduled principal payments on debt in year four	0
Scheduled principal payments on debt in year five	425,000,000
Scheduled principal payments on debt after year five	1,570,000,000
Principal	1,993,000,000	$ 1,993,000,000
Cash interest payments on long-term debt	92,000,000	83,000,000	$ 65,000,000
AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Revolving credit line	$ 500,000,000
Interest rate description for revolving credit facility	1.00% to 1.875% (currently 1.375%) over LIBOR
Amount borrowed under AFG revolving credit facility	$ 0	0
LIBOR \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Interest rate on revolving debt facility	1.375%
LIBOR \| AFG \| Minimum
Long-term Debt, Fiscal Year Maturity [Abstract]
Interest rate on revolving debt facility	1.00%
LIBOR \| AFG \| Maximum
Long-term Debt, Fiscal Year Maturity [Abstract]
Interest rate on revolving debt facility	1.875%
Senior Notes \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 1,318,000,000	1,318,000,000
Senior Notes \| 5.25% Senior Notes due April 2030 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 300,000,000	300,000,000					$ 300,000,000
Interest rate on debt instruments	5.25%						5.25%
Subordinated Debt \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 675,000,000	675,000,000
Subordinated Debt \| 4.50% Subordinated Debentures due September 2060 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 200,000,000	200,000,000			$ 200,000,000
Interest rate on debt instruments	4.50%				4.50%
Subordinated Debt \| 6% Subordinated Debentures Due November 2055 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Interest rate on debt instruments				6.00%
Senior Notes, amount of the original debt instrument that was redeemed				$ 150,000,000
Subordinated Debt \| 5.625% Subordinated Debentures due June 2060 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 150,000,000	150,000,000				$ 150,000,000
Interest rate on debt instruments	5.625%					5.625%
Subordinated Debt \| 5.125% Subordinated Debentures due December 2059 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 200,000,000	200,000,000	$ 200,000,000
Interest rate on debt instruments	5.125%		5.125%
Subordinated Debt \| 6-1/4% Subordinated Debentures due September 2054 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Interest rate on debt instruments			6.25%
Senior Notes, amount of the original debt instrument that was redeemed			$ 150,000,000
Subordinated Debt \| 5.875% Subordinated Debentures due March 2059 \| AFG
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal	$ 125,000,000	$ 125,000,000						$ 125,000,000
Interest rate on debt instruments	5.875%							5.875%