Condensed Financial Information of Parent Company (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Other Comprehensive Income [Abstract]
Net earnings attributable to shareholders	$ 158	$ 83	$ 110	$ 120	$ 50	$ 226	$ 99	$ 113	$ 471	$ 488	$ 342
Other comprehensive income (loss), net of tax									(271)	252	85
Comprehensive income attributable to shareholders									200	740	427
AFG [Member]
Statement of Other Comprehensive Income [Abstract]
Net earnings attributable to shareholders									471	488	342
Other comprehensive income (loss), net of tax									(271)	252	85
Comprehensive income attributable to shareholders									$ 200	$ 740	$ 427