Lending Activities - Credit Quality of Commercial Mortgages (Details) - Commercial mortgages - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]
2026	$ 40	$ 14
2025	14	38
2024	37	229
2023	231	117
2022	113	592
Prior	1,974	1,505
Total	$ 2,409	$ 2,495
Weighted average loan-to-value ratio (as a percent)	66.00%	71.00%
Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
2026	$ 40	$ 14
2025	14	38
2024	37	213
2023	226	94
2022	90	468
Prior	1,222	808
Total	1,629	1,635
65% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2026	0	0
2025	0	0
2024	0	11
2023	0	0
2022	0	77
Prior	512	463
Total	512	551
Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2026	0	0
2025	0	0
2024	0	5
2023	5	23
2022	23	47
Prior	240	234
Total	$ 268	$ 309