Segment Information - Supplemental Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net earned premiums	$ 494	$ 414	$ 485
Net investment income	269	269	297
Loss and LAE (benefit)	16	(220)	203
Amortization of DAC	14	14	16
Other Expenses	425	409	425
Operating Segments
Segment Reporting Information [Line Items]
Net earned premiums	497	418	490
Net investment income	278	280	310
Loss and LAE (benefit)	12	(221)	204
Amortization of DAC	14	14	16
Other Expenses	350	347	354
Operating Segments | Insurance
Segment Reporting Information [Line Items]
Net earned premiums	497	418	490
Net investment income	278	280	310
Loss and LAE (benefit)	12	(221)	204
Amortization of DAC	14	14	16
Other Expenses	232	240	226
Non-cash compensation and operating expenses	41	56	39
Operating Segments | Asset Management
Segment Reporting Information [Line Items]
Net earned premiums	0	0	0
Net investment income	0	0	0
Loss and LAE (benefit)	0	0	0
Amortization of DAC	0	0	0
Other Expenses	118	107	128
Non-cash compensation and operating expenses	18	17	31
Corporate division
Segment Reporting Information [Line Items]
Net earned premiums	0	0	0
Net investment income	4	2	2
Loss and LAE (benefit)	0	0	0
Amortization of DAC	0	0	0
Other Expenses	54	41	37
Non-cash compensation and operating expenses	13	5	6
Other Operating Segments And Intersegment Eliminations
Segment Reporting Information [Line Items]
Net earned premiums	(3)	(4)	(5)
Net investment income	(13)	(13)	(15)
Loss and LAE (benefit)	8	15	(3)
Amortization of DAC	0	0	0
Other Expenses	21	21	34
Subtotal
Segment Reporting Information [Line Items]
Net earned premiums	494	414	485
Net investment income	269	269	297
Loss and LAE (benefit)	20	(206)	201
Amortization of DAC	14	14	16
Other Expenses	425	409	425
Segment Reconciling Items
Segment Reporting Information [Line Items]
Net earned premiums	0	0	0
Net investment income	0	0	0
Loss and LAE (benefit)	(4)	(14)	2
Amortization of DAC	0	0	0
Other Expenses	$ 0	$ 0	$ 0