Investments (Financing Receivables Past Due) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 10,195	$ 8,952
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,020	8,952
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	175	0
Financial Asset, Not Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,961	8,934
Financial Asset, Not Past Due | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	175	0
Financial Asset, 30 to 59 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	4	12
Financial Asset, 60 to 89 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	26	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 29	$ 6