Amount of long-term debt maturing within the fifth full calendar year following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing within the fourth full calendar year following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing within the first full calendar year following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing within the third full calendar year following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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- Definition

Amount of long-term debt maturing within the second full calendar year following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing within the remaining current year period, which may include maturities of long-term debt, sinking fund requirements and other securities redeemable at fixed or determinable prices and dates.

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Long-term debt.

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- Definition

Interest rate stated in the contractual debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Topic 460
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-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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- Definition

Amount borrowed under the credit facility as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

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Increase for additional borrowings on the credit facility during the period.

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-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph f

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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Paragraph 2, 4
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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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- Definition

The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets or underlying collateral.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 10
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6513228

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Long-Term Debt (Details Textuals) (USD $) In Millions, unless otherwise specified	6 Months Ended									1 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010	Jun. 30, 2011 9-7/8% Senior Notes due June 2019 [Member]	Jun. 30, 2011 7% Senior Notes due September 2050 [Member]	Jun. 30, 2011 7-1/2% Senior Debentures due November 2033 [Member]	Jun. 30, 2011 7-1/4% Senior Debentures due January 2034 [Member]	Jun. 30, 2011 7-1/8% Senior Debentures due February 2034 [Member]	Jun. 30, 2011 10-7/8% Subordinated Notes due May 2011 [Member]	May 31, 2011 10-7/8% Subordinated Notes due May 2011 [Member] Subsidiaries [Member]
Debt Instrument [Line Items]
American Premier 10-7/8% Subordinated Notes due May 2011										$ 8
Interest rate on debt instruments				9.875%	7.00%	7.50%	7.25%	7.125%	10.875%
Long-Term Debt (Textuals) [Abstract]
Secured Borrowings guaranteed by AFG	17		18
Scheduled principal payments on debt in 2011	6
Scheduled principal payments on debt in 2012	34
Scheduled principal payments on debt in 2013	20
Scheduled principal payments on debt in 2014	2
Scheduled principal payments on debt in 2015	14
Scheduled principal payments on debt in 2016	45
AFG's revolving credit line	500
Interest rate range for revolving credit facility	1.75% to 3.00% (currently 2%) over LIBOR
Amount borrowed under AFG revolving credit facility	0
Amount borrowed under National Interstate bank credit facility		$ 30