Investments, Debt and Equity Securities (Age Analysis of Past Due Recorded Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 8,952	$ 7,459
Financial Asset, Not Past Due \| Commercial Real Estate Portfolio Segment
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	8,934	7,431
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	6	0
Financial Asset, 30 to 59 Days Past Due \| Commercial Real Estate Portfolio Segment
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 12	$ 28

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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+ Details