Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, net of impairments	$ 3,006		$ 2,211
Derivatives	127		159
DAC/VOBA and Sales inducements adjustment on available-for-sale securities	(837)		(593)
Premium deficiency reserve adjustment	(424)		(216)
Unrealized capital gains (losses), before tax	1,872		1,561
Deferred income tax asset (liability)	(265)		(199)
Unrealized capital gains (losses), after tax	1,607		1,362
Pension and other postretirement benefits liability, net of tax	3		4
AOCI	1,610	$ 1,292	$ 1,366
Other Contract
Debt Securities, Available-for-sale [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ 22