Segment Information - Segment Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Segment Reporting Information [Line Items]
Revenue, including adjustments	$ 228	$ 232	$ 678	$ 716
Total revenues	228	232	678	716
Total expenses	228	200	513	496
Income (loss) before income taxes and equity in earnings of investees	0	32	165	220
Equity in earnings of investees	23	7	66	3
Adjusted operating income (loss) before income taxes	23	39	231	223
Less: Provision (benefit) for income taxes	(14)	(12)	23	18
Noncontrolling interests	3	3	11	5
Adjusted operating income (loss)	34	48	197	200
Corporate
Segment Reporting Information [Line Items]
Revenue, including adjustments	1	12	1	8
Total revenues	1	12	1	8
Total expenses	211	32	279	99
Income (loss) before income taxes and equity in earnings of investees	(210)	(20)	(278)	(91)
Equity in earnings of investees	1	0	1	(5)
Adjusted operating income (loss) before income taxes	(209)	(20)	(277)	(96)
Less: Provision (benefit) for income taxes	(40)	(2)	(45)	(13)
Noncontrolling interests	0	0	0	0
Adjusted operating income (loss)	(169)	(18)	(232)	(83)
Other
Segment Reporting Information [Line Items]
Revenue, including adjustments	23	21	79	44
Total revenues	18	17	66	33
Total expenses	10	5	21	8
Income (loss) before income taxes and equity in earnings of investees	8	12	45	25
Equity in earnings of investees	(11)	(13)	(35)	(29)
Adjusted operating income (loss) before income taxes	(3)	(1)	10	(4)
Less: Provision (benefit) for income taxes	(2)	(1)	(1)	(2)
Noncontrolling interests	3	3	11	5
Adjusted operating income (loss)	(4)	(3)	0	(7)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	(5)	(4)	(13)	(11)
Insurance | Operating Segments
Segment Reporting Information [Line Items]
Revenue, including adjustments	187	186	544	623
Total revenues	190	189	551	631
Total expenses	(22)	134	131	308
Income (loss) before income taxes and equity in earnings of investees	212	55	420	323
Equity in earnings of investees	33	20	100	37
Adjusted operating income (loss) before income taxes	245	75	520	360
Less: Provision (benefit) for income taxes	31	(6)	75	40
Noncontrolling interests	0	0	0	0
Adjusted operating income (loss)	214	81	445	320
Insurance | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	3	3	7	8
Asset Management | Operating Segments
Segment Reporting Information [Line Items]
Revenue, including adjustments	17	13	54	41
Total revenues	19	14	60	44
Total expenses	29	29	82	81
Income (loss) before income taxes and equity in earnings of investees	(10)	(15)	(22)	(37)
Equity in earnings of investees	0	0	0	0
Adjusted operating income (loss) before income taxes	(10)	(15)	(22)	(37)
Less: Provision (benefit) for income taxes	(3)	(3)	(6)	(7)
Noncontrolling interests	0	0	0	0
Adjusted operating income (loss)	(7)	(12)	(16)	(30)
Asset Management | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	$ 2	$ 1	$ 6	$ 3