Segments of Operations (Details 1) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		$ 110		$ 132	$ 510		$ 392
Realized gains (losses) on securities		(16)		13	2		44
Realized gain (loss) on subsidiaries		5		0	(157)		0
Earnings before income taxes		99		145	355		436
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		15		46	125		133
Investment and other income, net		75	[1]	64	272	[1]	180
Earnings before realized gains (losses) and income taxes		90		110	397		313
Annuity [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		67		86	230		243
Run-off Long-term Care and Life [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		6		1	14		(3)
Other [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	[2]	(53)		(65)	(131)		(161)
Specialty Property and transportation [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		20		11	14		(1)
Specialty casualty [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		31		32	96		100
Specialty financial [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		26		21	72		46
Specialty Other [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		7		6	13		13
Other Lines [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	[3]	$ (69)		$ (24)	$ (70)		$ (25)

[1] Includes pretax income of $51 million (before noncontrolling interest) from the sale of the Le Pavillon Hotel in the second quarter of 2015.

[2] Primarily holding company expenses, including a $4 million loss on retirement of debt in the third quarter of 2015 and special charges of $12 million and $6 million in the third quarters of 2015 and 2014, respectively, to increase A&E reserves related to AFG’s former railroad and manufacturing operations. Also includes losses of managed investment entities attributable to noncontrolling interest of $29 million for the third quarter and $47 million for the first nine months of 2014. Following the adoption of new guidance in the first quarter of 2015, there are no longer earnings (losses) of managed investment entities that are attributable to noncontrolling interests. See Note A — “Accounting Policies — Managed Investment Entities.”

[3] Includes special charges of $67 million and $24 million in the third quarter of 2015 and 2014, respectively, to increase asbestos and environmental (“A&E”) reserves.