Segment Information - Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Revenue, including adjustments	$ 220	$ 190
Total revenues	220	190
Total expenses	174	146
Income (loss) before income taxes and equity in earnings of investees	46	44
Equity in earnings of investees	9	(4)
Adjusted operating income (loss) before income taxes	55	40
Provision (benefit) for income taxes	8	10
Noncontrolling interests	4	(3)
Adjusted operating income (loss)	43	33
Corporate
Segment Reporting Information [Line Items]
Revenue, including adjustments	0	(4)
Total revenues	0	(4)
Total expenses	32	35
Income (loss) before income taxes and equity in earnings of investees	(32)	(39)
Equity in earnings of investees	0	(5)
Adjusted operating income (loss) before income taxes	(32)	(44)
Provision (benefit) for income taxes	(3)	(5)
Noncontrolling interests	0	0
Adjusted operating income (loss)	(29)	(39)
Other
Segment Reporting Information [Line Items]
Revenue, including adjustments	25	(15)
Total revenues	21	(19)
Total expenses	7	(1)
Income (loss) before income taxes and equity in earnings of investees	14	(18)
Equity in earnings of investees	(10)	10
Adjusted operating income (loss) before income taxes	4	(8)
Provision (benefit) for income taxes	0	(1)
Noncontrolling interests	4	(3)
Adjusted operating income (loss)	0	(4)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	(4)	(4)
Insurance | Operating Segments
Segment Reporting Information [Line Items]
Revenue, including adjustments	177	193
Total revenues	179	196
Total expenses	106	84
Income (loss) before income taxes and equity in earnings of investees	73	112
Equity in earnings of investees	19	(9)
Adjusted operating income (loss) before income taxes	92	103
Provision (benefit) for income taxes	13	18
Noncontrolling interests	0	0
Adjusted operating income (loss)	79	85
Insurance | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	2	3
Asset Management | Operating Segments
Segment Reporting Information [Line Items]
Revenue, including adjustments	18	16
Total revenues	20	17
Total expenses	29	28
Income (loss) before income taxes and equity in earnings of investees	(9)	(11)
Equity in earnings of investees	0	0
Adjusted operating income (loss) before income taxes	(9)	(11)
Provision (benefit) for income taxes	(2)	(2)
Noncontrolling interests	0	0
Adjusted operating income (loss)	(7)	(9)
Asset Management | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue, including adjustments	$ 2	$ 1