Segments of Operations (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Segments of Operations (Textual) [Abstract]
Earnings (losses) of managed investment entities attributable to noncontrolling interests	$ (11)	[1]	$ (28)	[1]
Other [Member]
Segments of Operations (Textual) [Abstract]
Earnings (losses) of managed investment entities attributable to noncontrolling interests	$ (11)		$ (28)

[1] Included in Earnings before income taxes in AFG’s Statement of Earnings.