Segments - Operating Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 1,663	$ 1,969	$ 3,348	$ 3,791
Adjustments
Segment Reporting Information [Line Items]
Total revenues	438	574	726	1,067
Net realized investment gains (losses) and related charges and adjustments	41	42	33	55
Gains (losses) on change in fair value of derivatives related to guaranteed benefits	38	(5)	(52)	(9)
Revenues related to businesses exited or to be exited through reinsurance or divestment	332	417	676	815
Revenues attributable to noncontrolling interest	(66)	50	(57)	54
Other adjustments	93	70	125	152
Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,225	1,395	2,622	2,724
Operating Segments | Retirement
Segment Reporting Information [Line Items]
Total revenues	559	688	1,236	1,336
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Total revenues	129	163	294	311
Operating Segments | Employee Benefits
Segment Reporting Information [Line Items]
Total revenues	530	515	1,074	1,023
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Total revenues	7	29	18	54
Intersegment | Investment Management
Segment Reporting Information [Line Items]
Total revenues	$ 27	$ 25	$ 53	$ 51