Investments (Mortgage Loans Allowances Gross charge-offs by Portfolio Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	$ 54	$ 0
OriginatedInCurrentFiscalYear
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Originated In Fiscal Year Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Originated Two Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Originated Three Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Originated Four Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	1
Originated Five Or More Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	53
Agricultural Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	9	0
Agricultural Mortgage Loans \| OriginatedInCurrentFiscalYear
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Agricultural Mortgage Loans \| Originated In Fiscal Year Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Agricultural Mortgage Loans \| Originated Two Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Agricultural Mortgage Loans \| Originated Three Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Agricultural Mortgage Loans \| Originated Four Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Agricultural Mortgage Loans \| Originated Five Or More Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	9
Commercial Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	44	0
Commercial Mortgage Loans \| OriginatedInCurrentFiscalYear
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Commercial Mortgage Loans \| Originated In Fiscal Year Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Commercial Mortgage Loans \| Originated Two Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Commercial Mortgage Loans \| Originated Three Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Commercial Mortgage Loans \| Originated Four Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Commercial Mortgage Loans \| Originated Five Or More Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	44
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	1	$ 0
Residential Mortgage Loans \| OriginatedInCurrentFiscalYear
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Residential Mortgage Loans \| Originated In Fiscal Year Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Residential Mortgage Loans \| Originated Two Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Residential Mortgage Loans \| Originated Three Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	0
Residential Mortgage Loans \| Originated Four Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	1
Residential Mortgage Loans \| Originated Five Or More Years Before Latest Fiscal Year
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs, net of recoveries	$ 0