DAC, VOBA, DSI, and DFEL (DFEL) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in DFEL [Abstract]
Balance as of beginning-of-year	$ 1,952	$ 1,401	$ 1,938
Deferrals	631	539	402
Amortization, net of interest:
Amortization, excluding unlocking, net of interest	(365)	(308)	(335)
Unlocking	(63)	(68)	(50)
Adjustment related to realized (gains) losses	(3)	(4)	(6)
Adjustment related to unrealized (gains) losses	(278)	392	(548)
Balance as of end-of-year	$ 1,874	$ 1,952	$ 1,401