Investments - Components of the net unrealized gain on securities that is included in AOCI in the Balance Sheet (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Unrealized gain on:
Pretax		$ 588	$ 105
Deferred Tax		(124)	(22)
Net		464	83
Total fixed maturities
Unrealized gain on:
Pretax		1,013	160
Deferred Tax		(213)	(34)
Net		800	126
Fixed maturities — annuity segment
Unrealized gain on:
Pretax	[1]	792	101
Deferred Tax	[1]	(166)	(21)
Net	[1]	626	80
Fixed maturities — all other
Unrealized gain on:
Pretax		221	59
Deferred Tax		(47)	(13)
Net		174	46
Deferred policy acquisition costs — annuity segment
Unrealized gain on:
Pretax		(325)	(42)
Deferred Tax		68	9
Net		(257)	(33)
Annuity benefits accumulated
Unrealized gain on:
Pretax		(108)	(14)
Deferred Tax		23	3
Net		(85)	(11)
Unearned revenue
Unrealized gain on:
Pretax		8	1
Deferred Tax		(2)	0
Net		$ 6	$ 1

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