DAC, VOBA, DSI, and DFEL (VOBA) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in VOBA [Roll Forward]
Balance as of beginning-of-year		$ 499	$ 874	$ 873
Business acquired (sold) through reinsurance		(11)
Business acquired		30
Deferrals		7	7	3
Amortization:
Amortization, excluding unlocking		(127)	(105)	(105)
Unlocking		(60)	(48)	36
Accretion of interest	[1]	48	52	52
Adjustment related to realized gains (losses)		(2)	(1)	(2)
Adjustment related to unrealized gains (losses)		415	(280)	17
Balance as of end-of-year		$ 799	$ 499	$ 874
Interest accrual rate, low end		4.20%
Interest accrual rate, high end		6.90%

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