Deferred Policy Acquisition Costs and Value of Business Acquired (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning balance	$ 536	$ 385	$ 477
Deferrals of commissions and expenses	43	55	75
Amortization, excluding unlocking	(72)	(75)	(76)
Unlocking (1)	2	(26)	(61)
Interest accrued	35	35	37
Amortization:
Net amortization included in the Consolidated Statements of Operations	(35)	(66)	(100)
Change in unrealized capital gains/losses on available-for-sale securities	(256)	162	(67)
Ending balance	288	536	385
Movement Analysis Of Value of Business Acquired VOBA [Roll Forward]
Beginning balance	551	367	537
Deferrals of commissions and expenses	6	6	5
Amortization, excluding unlocking	(66)	(72)	(83)
Unlocking (1)	(2)	13	(93)
Interest accrued	38	39	43
Net amortization included in the Consolidated Statements of Operations	(30)	(20)	(133)
Change in unrealized capital gains/losses on available-for-sale securities	(222)	198	(42)
Ending balance	305	551	367
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Beginning balance	1,087	752	1,014
Deferrals of commissions and expenses	49	61	80
Amortization, excluding unlocking	(138)	(147)	(159)
Unlocking (1)	0	(13)	(154)
Interest accrued	73	74	80
Net amortization included in the Consolidated Statements of Operations	(65)	(86)	(233)
Change in unrealized capital gains/losses on available-for-sale securities	(478)	360	(109)
Ending balance	593	1,087	752
Estimated amount of VOBA amortization expense, net of interest:
2020	18
2021	16
2022	14
2023	14
2024	$ 14
Guaranteed Minimum Interest Rates
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Unlocking (1)		(25)	(80)
Movement Analysis Of Value of Business Acquired VOBA [Roll Forward]
Unlocking (1)		$ (26)	$ (140)
Minimum
Deferred Policy Acquisition Cost and Value of Business Acquired [Line Items]
Interest Accrual Rate Associated with Amortization Method of Present Value of Future Insurance Profits	5.50%	5.50%	5.50%
Maximum
Deferred Policy Acquisition Cost and Value of Business Acquired [Line Items]
Interest Accrual Rate Associated with Amortization Method of Present Value of Future Insurance Profits	7.00%	7.00%	7.00%