Investments - Unrealized net capital gains and losses included in AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair value
Fixed income securities:	$ 58,202	$ 57,170
Short-term investments	4,157	3,027
Derivative instruments	0	0
Gross unrealized Gains
Fixed income securities	1,635	993
Short-term investments	0	0
Derivative instruments	0	0
Gross unrealized Losses
Fixed income securities	(264)	(957)
Short-term investments	0	0
Derivative instruments	(3)	(3)
Unrealized net gains (losses)
Fixed income securities	1,371	36
Short-term investments	0	0
Derivative instruments	(3)	(3)
Unrealized net capital gains and losses, pre-tax	1,368	33
Amount recognized for:
Insurance reserves	(8)	0
DAC and DSI	(124)	(33)
Amounts recognized	(132)	(33)
Deferred income taxes	(264)	(2)
Total unrealized net capital gains and losses	$ 972	$ (2)