Accumulated Other Comprehensive Income - Detail of AOCI (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	$ 3,057	$ (585)
Deferred income taxes	(615)	113
Accumulated other comprehensive income (loss)	2,442	(472)
AFS securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	4,099	(766)
DAC, DSI, VOBA, future policy benefits and dividends payable to policyholders adjustments on AFS securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	(1,227)	154
Noncredit component of OTTI losses on AFS securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	(30)	(19)
Hedging instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	222	51
Pension adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	(3)	(2)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before taxes	$ (4)	$ (3)