Investments, Debt and Equity Securities (Age Analysis of Past Due Recorded Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 6,653	$ 6,329
Financial Asset, Not Past Due \| Commercial Real Estate Portfolio Segment
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	6,617	6,329
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 36	$ 0

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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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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+ Details