Investments (Credit Quality of Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	$ 843	$ 1,843
Financing receivable, originated in FY before latest FY	1,928	642
Financing receivable, originated two years before latest FY	577	4,376
Financing receivable, originated three years before latest FY	4,237	5,999
Financing receivable, originated four years before latest FY	5,720	986
Financing receivable, originated five or more years before latest FY	9,867	9,586
Financing receivable, before allowance for credit losses	23,172	23,432
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	390	848
Financing receivable, originated in FY before latest FY	847	199
Financing receivable, originated two years before latest FY	158	2,390
Financing receivable, originated three years before latest FY	2,328	3,152
Financing receivable, originated four years before latest FY	2,962	432
Financing receivable, originated five or more years before latest FY	6,227	6,305
Financing receivable, before allowance for credit losses	$ 12,912	$ 13,326
Financing receivable, before allowance for credit losses by debt service coverage ratio as a percentage of financing receivable, before allowance for credit losses	100.00%	100.00%
Commercial | Debt Service Coverage Ratio, Greater than 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, before allowance for credit losses	$ 11,310	$ 12,029
Financing receivable, before allowance for credit losses by debt service coverage ratio as a percentage of financing receivable, before allowance for credit losses	87.60%	90.30%
Commercial | Debt Service Coverage Ratio, 1.00x to 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, before allowance for credit losses	$ 931	$ 801
Financing receivable, before allowance for credit losses by debt service coverage ratio as a percentage of financing receivable, before allowance for credit losses	7.20%	6.00%
Commercial | Debt Service Coverage Ratio, Less than 1.00x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, before allowance for credit losses	$ 671	$ 496
Financing receivable, before allowance for credit losses by debt service coverage ratio as a percentage of financing receivable, before allowance for credit losses	5.20%	3.70%
Commercial | Loan-to-Value Ratio, Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	$ 286	$ 640
Financing receivable, originated in FY before latest FY	639	199
Financing receivable, originated two years before latest FY	158	279
Financing receivable, originated three years before latest FY	288	1,850
Financing receivable, originated four years before latest FY	1,826	196
Financing receivable, originated five or more years before latest FY	2,682	2,844
Financing receivable, before allowance for credit losses	5,879	6,008
Commercial | Loan-to-Value Ratio, 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	73	208
Financing receivable, originated in FY before latest FY	208	0
Financing receivable, originated two years before latest FY	0	1,022
Financing receivable, originated three years before latest FY	973	713
Financing receivable, originated four years before latest FY	701	62
Financing receivable, originated five or more years before latest FY	1,068	1,171
Financing receivable, before allowance for credit losses	3,023	3,176
Commercial | Loan-to-Value Ratio, 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	0	0
Financing receivable, originated in FY before latest FY	0	0
Financing receivable, originated two years before latest FY	0	117
Financing receivable, originated three years before latest FY	117	201
Financing receivable, originated four years before latest FY	165	174
Financing receivable, originated five or more years before latest FY	880	601
Financing receivable, before allowance for credit losses	1,162	1,093
Commercial | Loan-to-Value Ratio, Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	31	0
Financing receivable, originated in FY before latest FY	0	0
Financing receivable, originated two years before latest FY	0	972
Financing receivable, originated three years before latest FY	950	388
Financing receivable, originated four years before latest FY	270	0
Financing receivable, originated five or more years before latest FY	1,597	1,689
Financing receivable, before allowance for credit losses	2,848	3,049
Agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	126	408
Financing receivable, originated in FY before latest FY	356	221
Financing receivable, originated two years before latest FY	217	674
Financing receivable, originated three years before latest FY	663	1,186
Financing receivable, originated four years before latest FY	1,162	407
Financing receivable, originated five or more years before latest FY	1,959	1,667
Financing receivable, before allowance for credit losses	4,483	4,563
Agricultural | Loan-to-Value Ratio, Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	126	408
Financing receivable, originated in FY before latest FY	356	203
Financing receivable, originated two years before latest FY	200	594
Financing receivable, originated three years before latest FY	579	1,073
Financing receivable, originated four years before latest FY	1,051	400
Financing receivable, originated five or more years before latest FY	1,932	1,632
Financing receivable, before allowance for credit losses	4,244	4,310
Agricultural | Loan-to-Value Ratio, 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	0	0
Financing receivable, originated in FY before latest FY	0	18
Financing receivable, originated two years before latest FY	17	80
Financing receivable, originated three years before latest FY	84	113
Financing receivable, originated four years before latest FY	111	6
Financing receivable, originated five or more years before latest FY	26	19
Financing receivable, before allowance for credit losses	238	236
Agricultural | Loan-to-Value Ratio, 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	0	0
Financing receivable, originated in FY before latest FY	0	0
Financing receivable, originated two years before latest FY	0	0
Financing receivable, originated three years before latest FY	0	0
Financing receivable, originated four years before latest FY	0	1
Financing receivable, originated five or more years before latest FY	1	0
Financing receivable, before allowance for credit losses	1	1
Agricultural | Loan-to-Value Ratio, Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	0	0
Financing receivable, originated in FY before latest FY	0	0
Financing receivable, originated two years before latest FY	0	0
Financing receivable, originated three years before latest FY	0	0
Financing receivable, originated four years before latest FY	0	0
Financing receivable, originated five or more years before latest FY	0	16
Financing receivable, before allowance for credit losses	0	16
Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	327	587
Financing receivable, originated in FY before latest FY	725	222
Financing receivable, originated two years before latest FY	202	1,312
Financing receivable, originated three years before latest FY	1,246	1,661
Financing receivable, originated four years before latest FY	1,596	147
Financing receivable, originated five or more years before latest FY	1,681	1,614
Financing receivable, before allowance for credit losses	5,777	5,543
Residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	327	586
Financing receivable, originated in FY before latest FY	725	222
Financing receivable, originated two years before latest FY	202	1,268
Financing receivable, originated three years before latest FY	1,206	1,640
Financing receivable, originated four years before latest FY	1,571	146
Financing receivable, originated five or more years before latest FY	1,637	1,563
Financing receivable, before allowance for credit losses	5,668	5,425
Residential | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, originated in current FY	0	1
Financing receivable, originated in FY before latest FY	0	0
Financing receivable, originated two years before latest FY	0	44
Financing receivable, originated three years before latest FY	40	21
Financing receivable, originated four years before latest FY	25	1
Financing receivable, originated five or more years before latest FY	44	51
Financing receivable, before allowance for credit losses	$ 109	$ 118