Investments - Unrealized net capital gains and losses included in AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair value
Fixed income securities:	$ 56,674	$ 58,992
Equity securities	6,986	6,621
Short-term investments	3,424	1,944
Derivative instruments	2	2
Gross unrealized Gains
Fixed income securities	1,210	1,750
Equity securities		1,172
Short-term investments	0	0
Derivative instruments	2	2
Gross unrealized Losses
Fixed income securities	(745)	(283)
Equity securities		(12)
Short-term investments	0	0
Derivative instruments	(3)	(3)
Unrealized net gains (losses)
Fixed income securities	465	1,467
Equity securities		1,160
Short-term investments	0	0
Derivative instruments	(1)	(1)
EMA limited partnerships	1	1
Unrealized net capital gains and losses, pre-tax	465	2,627
Amount recognized for:
Insurance reserves	(119)	(315)
DAC and DSI	(109)	(196)
Amounts recognized	(228)	(511)
Deferred income taxes	(50)	(454)
Total unrealized net capital gains and losses	187	1,662
Fair value of derivative liabilities with unrealized net capital gain (loss)	$ 2	$ 2