DAC, VOBA, DSI, and DFEL (DFEL) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in DFEL [Abstract]
Balance as of beginning-of-year	$ 1,429	$ 1,855	$ 1,923
Deferrals	874	753	628
Amortization, net of interest:
Amortization, excluding unlocking, net of interest	(474)	(383)	(345)
Unlocking	(52)	(3)	(63)
Adjustment related to realized (gains) losses	(19)	(18)	(11)
Adjustment related to unrealized (gains) losses	1,005	(775)	(277)
Balance as of end-of-year	$ 2,763	$ 1,429	$ 1,855