Investments - Residential Mortgage Loans by Year of Origination (Details) - Residential - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	$ 1,156	$ 1,909
Year two	2,002	573
Year three	475	525
Year four	475	438
Year five	406	69
Year six and prior	214	150
Total	4,728	3,664
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	1,156	1,895
Year two	1,951	557
Year three	455	492
Year four	443	427
Year five	392	65
Year six and prior	203	136
Total	4,600	3,572
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0	14
Year two	51	16
Year three	20	33
Year four	32	11
Year five	14	4
Year six and prior	11	14
Total	$ 128	$ 92