Segments of Operations (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	$ 132		$ 86		$ 392		$ 289
Realized gains on securities	13		56		44		154
Earnings before income taxes	145		142		436		443
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	46		8		133		70
Investment and other income, net	64		53		180		169
Earnings before realized gains (losses) and income taxes	110		61		313		239
Annuity [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	86		78	[1]	243		231	[1]
Run-off Long-term Care and Life [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	1		(4)		(3)		(7)
Other [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	(65)	[2]	(49)	[2]	(161)	[2]	(174)	[2]
Specialty Property and transportation [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	11		16		(1)		(5)
Specialty casualty [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	32		19		100		70
Specialty financial [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	21		22		46		50
Specialty Other [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	6		5		13		16
Other Lines [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	$ (24)	[3]	$ (54)	[3]	$ (25)	[3]	$ (61)	[3]

[1] Includes a $5 million charge in the second quarter of 2013 to cover expected assessments from state guaranty funds related to the insolvency and liquidation of an unaffiliated life insurance company.

[2] Includes holding company expenses and earnings (losses) of managed investment entities attributable to noncontrolling interest of ($29) million and $12 million for the third quarter and ($47) million and ($30) million for the first nine months of 2014 and 2013, respectively. Holding company expenses includes special charges totaling $6 million in the third quarter of 2014 and $22 million in the third quarter of 2013 to increase A&E reserves related to AFG’s former railroad and manufacturing operations.

[3] Includes special charges of $24 million and $54 million in the third quarter of 2014 and 2013, respectively, to increase asbestos and environmental (“A&E”) reserves.