Segment Information - Segment Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Sep. 30, 2019 segment
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2		1
Revenue, ancluding adjustments	$ 190	$ 234
Total revenues	190	234
Total expenses	146	138
Income (loss) before income taxes and equity in net earnings of investees	44	96
Equity in net earnings of investees	(4)	2
Adjusted operating income (loss) before income taxes	40	98
Provision (benefit) for income taxes	10	12
Less: Noncontrolling interests	(3)	0
Adjusted Income (Loss) Attributable to Parent	33	86
Net investment income	80	98
Interest expense	22	23
Non-cash compensation and operating expenses	15	12
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	(4)	0
Total revenues	(4)	0
Total expenses	35	31
Income (loss) before income taxes and equity in net earnings of investees	(39)	(31)
Equity in net earnings of investees	(5)	1
Adjusted operating income (loss) before income taxes	(44)	(30)
Provision (benefit) for income taxes	(5)	(5)
Less: Noncontrolling interests	0	0
Adjusted Income (Loss) Attributable to Parent	(39)	(25)
Net investment income	1	1
Interest expense	25	24
Non-cash compensation and operating expenses	3	1
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	(15)	1
Total revenues	(19)	0
Total expenses	(1)	0
Income (loss) before income taxes and equity in net earnings of investees	(18)	0
Equity in net earnings of investees	10	0
Adjusted operating income (loss) before income taxes	(8)	0
Provision (benefit) for income taxes	(1)	0
Less: Noncontrolling interests	(3)	0
Adjusted Income (Loss) Attributable to Parent	(4)	0
Net investment income	(4)	(2)
Interest expense	(3)	(1)
Non-cash compensation and operating expenses	0	0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	(4)	(1)
Insurance Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	193	233
Total revenues	196	234
Total expenses	84	107
Income (loss) before income taxes and equity in net earnings of investees	112	127
Equity in net earnings of investees	(9)	1
Adjusted operating income (loss) before income taxes	103	128
Provision (benefit) for income taxes	18	17
Less: Noncontrolling interests	0	0
Adjusted Income (Loss) Attributable to Parent	85	111
Net investment income	83	99
Interest expense	0	0
Non-cash compensation and operating expenses	9	11
Insurance Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	3	1
Asset Management [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	16	0
Total revenues	17	0
Total expenses	28	0
Income (loss) before income taxes and equity in net earnings of investees	(11)	0
Equity in net earnings of investees	0	0
Adjusted operating income (loss) before income taxes	(11)	0
Provision (benefit) for income taxes	(2)	0
Less: Noncontrolling interests	0	0
Adjusted Income (Loss) Attributable to Parent	(9)	0
Net investment income	0	0
Interest expense	0	0
Non-cash compensation and operating expenses	3	$ 0
Asset Management [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, ancluding adjustments	$ 1