Shareholders' Equity (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Components of accumulated other comprehensive income
Unrealized holding gains (losses) on securities arising during the period, pretax	$ 200		$ (378)		$ 411		$ (256)
Unrealized holding gains (losses) on securities arising during the period, tax	(70)		133		(144)		90
Unrealized holding gains (losses) on securities arising during the period, net of tax	130		(245)		267		(166)
Unrealized holding gains (losses) on securities arising during the period, attributable to noncontrolling interests	(3)		6		(6)		5
Unrealized holding gains (losses) on securities arising during the period, attributable to shareholders	127		(239)		261		(161)
Reclassification adjustment for realized gains (losses) included in net earnings, pretax	(12)	[1]	(41)	[1]	(30)	[1]	(97)	[1]
Reclassification adjustment for realized gains (losses) included in net earnings, tax	4	[1]	14	[1]	10	[1]	34	[1]
Reclassification adjustment for realized gains (losses) included in net earnings, net of tax	(8)		(27)		(20)		(63)
Reclassification adjustment for realized gains (losses) included in net earnings, attributable to noncontrolling interests	1	[1]	1	[1]	1	[1]	1	[1]
Reclassification adjustment for realized gains (losses) included in net earnings, attributable to shareholders	(7)		(26)		(19)		(62)
Accumulated other comprehensive income, net unrealized gains on securities, beginning balance	685	[2]	865		563	[2]	823
Other comprehensive income, net unrealized gains on securities, pretax	188		(419)		381		(353)
Other comprehensive income, net unrealized gains on securities, tax	(66)		147		(134)		124
Total net unrealized gains (losses) on securities	122		(272)		247		(229)
Other comprehensive income, net unrealized gains on securities, attributable to noncontrolling interests	(2)		7		(5)		6
Other comprehensive income, net unrealized gains on securities, attributable to shareholders	120		(265)		242		(223)
Accumulated other comprehensive income, net unrealized gains on securities, ending balance	805	[2]	600		805	[2]	600
Accumulated other comprehensive income, foreign currency translation adjustments, beginning balance	(4)		10		1		14
Other comprehensive income, foreign currency translation adjustments, pretax	2		(5)		(3)		(9)
Other comprehensive income, foreign currency translation adjustments, net of tax	2		(5)		(3)		(9)
Other comprehensive income, foreign currency translation adjustments, attributable to noncontrolling interests
Other comprehensive income, foreign currency translation adjustments, attributable to shareholders	2		(5)		(3)		(9)
Accumulated other comprehensive income, foreign currency translation adjustments, ending balance	(2)		5		(2)		5
Accumulated other comprehensive income, pension and other postretirement plans adjustments, beginning balance	(4)		(6)		(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)		(4)		(6)
Accumulated other comprehensive income, total, beginning balance	677		869		560		831
Other comprehensive income, total, pretax	190		(424)		378		(362)
Other comprehensive income, total, tax	(66)		147		(134)		124
Other comprehensive income (loss), net of tax	124		(277)		244		(238)
Other comprehensive income, total, attributable to noncontrolling interests	(2)		7		(5)		6
Other comprehensive income, total, attributable to shareholders	122		(270)		239		(232)
Accumulated other comprehensive income, total, ending balance	$ 799		$ 599		$ 799		$ 599

[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 $60 million at June 30, 2014, $58 million at March 31, 2014 and $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.