Deferred Policy Acquisition Costs and Value of Business Acquired - DAC and VOBA Activity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning balance	$ 1,762	$ 2,155
Deferrals of commissions and expenses	26	23
Amortization:
Amortization, excluding unlocking	(74)	(88)
Unlocking	(12)	7
Interest accrued	31	31
Net amortization included in the Consolidated Statements of Operations	(55)	(50)
Change due to unrealized capital gains/losses on available-for-sale securities	226	(185)
Ending balance	1,962	1,943
Movement Analysis Of Value of Business Acquired VOBA [Roll Forward]
Beginning balance	464	818
Deferrals of commissions and expenses	0	2
Amortization:
Amortization, excluding unlocking	(22)	(36)
Unlocking	(13)	15
Interest accrued	14	14
Net amortization included in Condensed Consolidated Statements of Operations	(21)	(7)
Change due to unrealized capital gains/losses on available-for-sale securities	198	(146)
Ending balance	641	667
Movement Analysis of Deferred Policy Acquisition Costs and Value of Business Acquired (VOBA) [Roll Forward]
Beginning balance	2,226	2,973
Deferrals of commissions and expenses	26	25
Amortization:
Amortization, excluding unlocking	(96)	(124)
Unlocking	(25)	22
Interest accrued	45	45
Net amortization included in Condensed Consolidated Statements of Operations	(76)	(57)
Change due to unrealized capital gains/losses on available-for-sale securities	424	(331)
Ending balance	$ 2,603	$ 2,610
Minimum
Amortization:
Value of Business Acquired (VOBA), Interest accrued percentage	3.50%	3.50%
Maximum
Amortization:
Value of Business Acquired (VOBA), Interest accrued percentage	7.40%	7.40%
Accounting Standards Update 2016-13
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning balance	$ 3
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	$ 3