Investments - Components of the net unrealized gain on securities that is included in AOCI in the Balance Sheet (Details) - USD ($) $ in Millions		Jun. 30, 2017	Dec. 31, 2016
Unrealized gain on:
Pretax		$ 983	$ 622
Deferred Tax		(344)	(218)
Net		639	404
Total investments
Unrealized gain on:
Pretax		1,516	960
Deferred Tax		(531)	(336)
Net		985	624
Total fixed maturities
Unrealized gain on:
Pretax		1,273	809
Deferred Tax		(446)	(283)
Net		827	526
Fixed maturities — annuity segment
Unrealized gain on:
Pretax	[1]	1,018	640
Deferred Tax	[1]	(356)	(224)
Net	[1]	662	416
Fixed maturities — all other
Unrealized gain on:
Pretax		255	169
Deferred Tax		(90)	(59)
Net		165	110
Equity securities
Unrealized gain on:
Pretax		243	151
Deferred Tax		(85)	(53)
Net		158	98
Deferred policy acquisition costs — annuity segment
Unrealized gain on:
Pretax		(421)	(273)
Deferred Tax		147	96
Net		(274)	(177)
Annuity benefits accumulated
Unrealized gain on:
Pretax		(130)	(78)
Deferred Tax		46	27
Net		(84)	(51)
Unearned revenue
Unrealized gain on:
Pretax		18	13
Deferred Tax		(6)	(5)
Net		$ 12	$ 8

[1] Net unrealized gains on fixed maturity investments supporting AFG’s annuity benefits accumulated.