Shareholders' Equity (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Components of accumulated other comprehensive income
Unrealized holding gains (losses) on securities arising during the period, pretax	$ 211		$ 122
Unrealized holding gains (losses) on securities arising during the period, tax	(74)		(43)
Unrealized holding gains (losses) on securities arising during the period, net of tax	137		79
Unrealized holding gains (losses) on securities arising during the period, attributable to noncontrolling interests	(3)		(1)
Unrealized holding gains (losses) on securities arising during the period, attributable to shareholders	134		78
Reclassification adjustment for realized gains (losses) included in net earnings, pretax	(18)	[1]	(56)	[1]
Reclassification adjustment for realized gains (losses) included in net earnings, tax	6	[1]	20	[1]
Reclassification adjustment for realized gains (losses) included in net earnings, net of tax	(12)		(36)
Reclassification adjustment for realized gains (losses) included in net earnings, attributable to noncontrolling interests		[1]		[1]
Reclassification adjustment for realized gains (losses) included in net earnings, attributable to shareholders	(12)		(36)
Accumulated other comprehensive income, net unrealized gains on securities, beginning balance	563	[2]	823
Other comprehensive income, net unrealized gains on securities, pretax	193		66
Other comprehensive income, net unrealized gains on securities, tax	(68)		(23)
Total net unrealized gains on securities	125		43
Other comprehensive income, net unrealized gains on securities, attributable to noncontrolling interests	(3)		(1)
Other comprehensive income, net unrealized gains on securities, attributable to shareholders	122		42
Accumulated other comprehensive income, net unrealized gains on securities, ending balance	685	[2]	865
Accumulated other comprehensive income, foreign currency translation adjustments, beginning balance	1		14
Other comprehensive income, foreign currency translation adjustments, pretax	(5)		(4)
Other comprehensive income, foreign currency translation adjustments, net of tax	(5)		(4)
Other comprehensive income, foreign currency translation adjustments, attributable to noncontrolling interests
Other comprehensive income, foreign currency translation adjustments, attributable to shareholders	(5)		(4)
Accumulated other comprehensive income, foreign currency translation adjustments, ending balance	(4)		10
Accumulated other comprehensive income, pension and other postretirement plans adjustments, beginning balance	(4)		(6)
Other comprehensive income, pension and other postretirement plans adjustments, pretax
Other comprehensive income, pension and other postretirement plans adjustments, tax
Other comprehensive income, pension and other postretirement plans adjustments, net of tax
Other comprehensive income, pension and other postretirement plans adjustments, attributable to shareholders
Accumulated other comprehensive income, pension and other postretirement plans adjustments, ending balance	(4)		(6)
Accumulated other comprehensive income, total, beginning balance	560		831
Other comprehensive income, total, pretax	188		62
Other comprehensive income, total, tax	(68)		(23)
Other comprehensive income, net of tax	120		39
Other comprehensive income, total, attributable to noncontrolling interests	(3)		(1)
Other comprehensive income, total, attributable to shareholders	117		38
Accumulated other comprehensive income, total, ending balance	$ 677		$ 869

[1] The reclassification adjustment out of net unrealized gains on securities affected the following lines in AFG’s Consolidated Statement of Earnings: OCI component Affected line in the Consolidated Statement of Earnings Pretax Realized gains on securities Tax Provision for income taxes Attributable to noncontrolling interests Net earnings (loss) attributable to noncontrolling interests

[2] Includes net unrealized gains of $58 million at March 31, 2014 compared to $54 million at December 31, 2013 related to securities for which only the credit portion of an other-than-temporary impairment has been recorded in earnings.