DAC, VOBA, DSI, and DFEL (DAC) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in DAC [Roll Forward]
Balance as of beginning-of-year	$ 9,448	$ 7,887	$ 8,243
Business acquired (sold) through reinsurance		(246)
Deferrals	1,902	1,600	1,348
Amortization, net of interest:
Amortization, excluding unlocking, net of interest	(950)	(951)	(965)
Unlocking	(489)	(115)	61
Adjustment related to realized gains (losses)	54	(47)	(12)
Adjustment related to unrealized gains (losses)	(2,613)	1,320	(788)
Balance as of end-of-year	$ 7,352	$ 9,448	$ 7,887