Investments - Unrealized net capital gains and losses (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair value
Fixed income securities	$ 21,400	$ 23,261
Equity securities	1,325	1,614
Short-term investments	810	725
Derivative instruments	0	2
Gross unrealized Gains
Fixed income securities	732	1,355
Equity securities		311
Short-term investments	0	0
Derivative instruments	0	2
Gross unrealized Losses
Fixed income securities	(389)	(98)
Equity securities		(3)
Short-term investments	0	0
Derivative instruments	0	0
Unrealized net gains (losses)
Fixed income securities	343	1,257
Equity securities		308
Short-term investments	0	0
Derivative instruments	0	2
EMA limited partnerships	0	1
Unrealized net capital gains and losses, pre-tax	343	1,568
Amounts recognized for:
Amounts recognized for:	0	(315)
DAC and DSI	(35)	(189)
Amounts recognized	(35)	(504)
Deferred income taxes	(65)	(229)
Total unrealized net capital gains and losses	$ 243	835
Fair value of derivative liabilities with unrealized net capital gain (loss)		$ 2