Investments - Components of the net unrealized gain on securities that is included in AOCI in the Balance Sheet (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Unrealized gain on:
Pretax		$ 813	$ 622
Deferred Tax		(284)	(218)
Net		529	404
Total investments
Unrealized gain on:
Pretax		1,234	960
Deferred Tax		(432)	(336)
Net		802	624
Total fixed maturities
Unrealized gain on:
Pretax		1,011	809
Deferred Tax		(354)	(283)
Net		657	526
Fixed maturities — annuity segment
Unrealized gain on:
Pretax	[1]	800	640
Deferred Tax	[1]	(280)	(224)
Net	[1]	520	416
Fixed maturities — all other
Unrealized gain on:
Pretax		211	169
Deferred Tax		(74)	(59)
Net		137	110
Equity securities
Unrealized gain on:
Pretax		223	151
Deferred Tax		(78)	(53)
Net		145	98
Deferred policy acquisition costs — annuity segment
Unrealized gain on:
Pretax		(333)	(273)
Deferred Tax		117	96
Net		(216)	(177)
Annuity benefits accumulated
Unrealized gain on:
Pretax		(103)	(78)
Deferred Tax		36	27
Net		(67)	(51)
Unearned revenue
Unrealized gain on:
Pretax		15	13
Deferred Tax		(5)	(5)
Net		$ 10	$ 8

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