DAC, VOBA, DSI, and DFEL (VOBA) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in VOBA [Roll Forward]
Balance as of beginning-of-year		$ 816	$ 516	$ 891
Business acquired (sold) through reinsurance			(11)
Business acquired			30
Deferrals		6	7	7
Amortization:
Amortization, excluding unlocking		(114)	(127)	(105)
Unlocking		140	(60)	(48)
Accretion of interest	[1]	45	48	52
Adjustment related to realized (gains) losses		(1)	(2)	(1)
Adjustment related to unrealized (gains) losses		(550)	415	(280)
Balance as of end-of-year		$ 342	$ 816	$ 516
Interest accrual rate, low end		4.20%	4.20%	4.20%
Interest accrual rate, high end		6.90%	6.90%	6.90%

[1] The interest accrual rates utilized to calculate the accretion of interest ranged from 4.2% to 6.9%.