Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Derivatives	$ 117	$ 140	$ 124
DAC/VOBA and Sales inducements adjustments on available-for-sale securities	(551)	(73)	(433)
Premium deficiency reserve adjustment	(211)	(51)	(115)
Other	0	0	5
Unrealized capital gains (losses), before tax	1,468	143	1,047
Deferred income tax asset (liability)	(180)	(39)	(234)
Unrealized capital gains (losses), after tax	1,288	104	813
Pension and other postretirement benefits liability, net of tax	4	4	5
AOCI	1,292	108	818
Fixed maturities
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Fixed maturities, net of OTTI	2,113	127	1,451
Equity securities
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Equity securities	0	$ 0	$ 15
Other Contract
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ 23