Investments - Investments - ACL on Mortgages (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of loans held-for-sale	0		0		0
us-gaap_FinancingReceivableModificationsNumberOfContracts2	1	0	1	0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Modified in Period, to Total Financing Receivables, Percentage	100.00%		100.00%
Beginning balance	$ (49)	$ (43)	$ (49)	$ (44)
Current period provision	0	6	0	6
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	0	(1)
Ending balance	(49)	$ (49)	(49)	$ (49)	$ (49)
Commercial Loan [Member] \| Extended Maturity
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Modified in Period, Amount	$ 30		$ 30

Financing Receivable, Modifications, Number Of Contracts

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Percentage of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

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Amortized cost of financing receivable modified during period for debtor experiencing financial difficulty.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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