Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Deferred tax assets:
Federal net operating loss carryforwards	$ 51		$ 51
Foreign underwriting losses	56		50
Insurance claims and reserves	746		558
Employee benefits	107		98
Other, net	26		51
Total deferred tax assets before valuation allowance	986		808
Valuation allowance against deferred tax assets	(109)		(103)
Total deferred tax assets	877		705
Deferred tax liabilities:
Subsidiaries not in AFG’s tax return	(61)	[1]	(60)	[1]
Investment securities	(663)		(443)
Deferred policy acquisition costs	(178)		(234)
Total deferred tax liabilities	(902)		(737)
Net deferred tax liability	$ (25)		$ (32)

[1] Related to National Interstate Corporation, a 51%-owned subsidiary.