Investments (Mortgage Loans by Credit Quality Indicator) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 10,652	$ 8,952
Construction Loan	$ 0	$ 53
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%	100.00%
Real Estate Loans On A Nonaccrual Status	$ 41		$ 23
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 10,408	$ 8,952
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	97.70%	100.00%
Mortgage Loans By Credit Quality Indicator Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 4,255
Construction Loan	$ 0	$ 7
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	48.20%	47.50%
Mortgage Loans By Credit Quality Indicator Range One [Member] \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 5,011
Mortgage Loans By Credit Quality Indicator Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 2,579
Construction Loan	$ 0	$ 46
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	29.20%	28.80%
Mortgage Loans By Credit Quality Indicator Range Two [Member] \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 3,041
Mortgage Loans By Credit Quality Indicator Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 1,430
Construction Loan	$ 0	$ 0
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	15.60%	16.00%
Mortgage Loans By Credit Quality Indicator Range Three [Member] \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,626
Mortgage Loans By Credit Quality Indicator Range Four [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 688
Construction Loan	$ 0	$ 0
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	7.00%	7.70%
Mortgage Loans By Credit Quality Indicator Range Four [Member] \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 730
Debt Service Coverage Ratio Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,135	$ 8,043
Debt Service Coverage Ratio Range One [Member] \| Mortgage Loans By Credit Quality Indicator Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,652	4,017
Debt Service Coverage Ratio Range One [Member] \| Mortgage Loans By Credit Quality Indicator Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,803	2,298
Debt Service Coverage Ratio Range One [Member] \| Mortgage Loans By Credit Quality Indicator Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,279	1,205
Debt Service Coverage Ratio Range One [Member] \| Mortgage Loans By Credit Quality Indicator Range Four [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	401	523
Debt Service Coverage Ratio Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	783	596
Debt Service Coverage Ratio Range Two [Member] \| Mortgage Loans By Credit Quality Indicator Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	212	189
Debt Service Coverage Ratio Range Two [Member] \| Mortgage Loans By Credit Quality Indicator Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	134	184
Debt Service Coverage Ratio Range Two [Member] \| Mortgage Loans By Credit Quality Indicator Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	261	178
Debt Service Coverage Ratio Range Two [Member] \| Mortgage Loans By Credit Quality Indicator Range Four [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	176	45
Debt Service Coverage Ratio Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	490	260
Debt Service Coverage Ratio Range Three [Member] \| Mortgage Loans By Credit Quality Indicator Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	147	42
Debt Service Coverage Ratio Range Three [Member] \| Mortgage Loans By Credit Quality Indicator Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	104	51
Debt Service Coverage Ratio Range Three [Member] \| Mortgage Loans By Credit Quality Indicator Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	86	47
Debt Service Coverage Ratio Range Three [Member] \| Mortgage Loans By Credit Quality Indicator Range Four [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 153	$ 120