Investments - Unrealized net capital gains and losses included in AOCI (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair value
Fixed income securities:	$ 56,891	$ 58,992
Short-term investments	3,123	1,944
Derivative instruments	0	2
Gross unrealized Gains
Fixed income securities	1,008	1,750
Equity securities		1,172
Short-term investments	0	0
Derivative instruments	0	2
Gross unrealized Losses
Fixed income securities	(867)	(283)
Equity securities		(12)
Short-term investments	0	0
Derivative instruments	(3)	(3)
Unrealized net gains (losses)
Fixed income securities	141	1,467
Equity securities		1,160
Short-term investments	0	0
Derivative instruments	(3)	(1)
EMA limited partnerships	3	1
Unrealized net capital gains and losses, pre-tax	141	2,627
Equity Securities, FV-NI	6,888	6,621
Amount recognized for:
Insurance reserves	0	(315)
DAC and DSI	(72)	(196)
Amounts recognized	(72)	(511)
Deferred income taxes	(15)	(454)
Total unrealized net capital gains and losses	$ 54	1,662
Fair value of derivative liabilities with unrealized net capital gain (loss)		$ 2