Investments (Financing Receivables Past Due) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 8,493	$ 7,459
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,441	7,431
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	23	28
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	6	0
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 23	$ 0