Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Additional Information (Textual) [Abstract]
Charges for possible losses on reinsurance recoverables, maximum	$ 1	$ 1	$ 1
Aggregate allowance for losses on reinsurance recoverables	26	26
Total rental expense	51	54	42
Operating lease future minimum payments due in 2013	54
Operating lease future minimum payments due in 2014	52
Operating lease future minimum payments due in 2015	44
Operating lease future minimum payments due in 2016	38
Operating lease future minimum payments due in 2017	31
Operating lease future minimum payments due after five years	185
Commitments to fund limited partnerships	75
Maximum amount of dividends available to be paid by insurance subsidiaries to AFG without prior approval of regulatory authorities	395
Retirement and employee savings plan expense	$ 27	$ 26	$ 30