Deferred Policy Acquisition Costs and Value of Business Acquired - Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning balance			$ 288	$ 536
Deferrals of commissions and expenses			28	27
Amortization:
Amortization, excluding unlocking			(45)	(31)
Unlocking			6	2
Interest accrued			18	18
Net amortization included in the Condensed Consolidated Statements of Operations			(21)	(11)
Change due to unrealized capital gains/losses on available-for-sale securities			(86)	(203)
Ending balance	$ 211	$ 349	211	349
Movement Analysis Of Value of Business Acquired VOBA [Roll Forward]
Beginning balance			305	551
Deferrals of commissions and expenses			2	3
Amortization, excluding unlocking			(40)	(27)
Unlocking			0	10
Interest accrued			18	19
Net amortization included in the Condensed Consolidated Statements of Operations			(22)	2
Change due to unrealized capital gains/losses on available-for-sale securities			(101)	(183)
Ending balance	184	373	184	373
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Beginning balance			593	1,087
Deferrals of commissions and expenses			30	30
Amortization, excluding unlocking			(85)	(58)
Unlocking			6	12
Interest accrued			36	37
Net amortization included in the Condensed Consolidated Statements of Operations	(6)	(3)	(43)	(9)
Change due to unrealized capital gains/losses on available-for-sale securities			(187)	(386)
Ending balance	$ 395	$ 722	$ 395	$ 722
Minimum
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Value of Business Acquired (VOBA), Interest accrued percentage			5.50%	5.50%
Maximum
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Value of Business Acquired (VOBA), Interest accrued percentage			7.00%	7.00%
Accounting Standards Update 2016-13
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning balance			$ 2
Movement Analysis Of Value of Business Acquired VOBA [Roll Forward]
Beginning balance			0
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Beginning balance			$ 2