Condensed Consolidating Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	$ 88	$ 54
Other comprehensive income, net of tax	138	25
Total comprehensive income, net of tax	226	79
Less: Comprehensive income (loss) attributable to noncontrolling interests	(21)	(34)
Comprehensive income attributable to shareholders	247	113
AFG [Member]
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	113	88
Other comprehensive income, net of tax	134	25
Total comprehensive income, net of tax	247	113
Less: Comprehensive income (loss) attributable to noncontrolling interests
Comprehensive income attributable to shareholders	247	113
GAFRI [Member]
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	49	30
Other comprehensive income, net of tax	119	18
Total comprehensive income, net of tax	168	48
Less: Comprehensive income (loss) attributable to noncontrolling interests
Comprehensive income attributable to shareholders	168	48
AAG Holding [Member]
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	49	31
Other comprehensive income, net of tax	117	18
Total comprehensive income, net of tax	166	49
Less: Comprehensive income (loss) attributable to noncontrolling interests
Comprehensive income attributable to shareholders	166	49
All Other Subs [Member]
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	116	81
Other comprehensive income, net of tax	138	24
Total comprehensive income, net of tax	254	105
Less: Comprehensive income (loss) attributable to noncontrolling interests	(21)	(34)
Comprehensive income attributable to shareholders	275	139
Consol. Entries [Member]
Condensed Consolidated Statement of Comprehensive Income
Net earnings, including noncontrolling interests	(239)	(176)
Other comprehensive income, net of tax	(370)	(60)
Total comprehensive income, net of tax	(609)	(236)
Less: Comprehensive income (loss) attributable to noncontrolling interests
Comprehensive income attributable to shareholders	$ (609)	$ (236)

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 3

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Research Bulletin (ARB)

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-Appendix A

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Comprehensive Income

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-Name Accounting Standards Codification

-Glossary Net Income

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

+ Details

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to noncontrolling interests, if any. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

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+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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+ Details