Investments (Changes In Allowance For Credit Losses On Mortgage Loans On Real Estate) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Investments [Line Items]
Balance as of beginning-of-year	$ 98,000,000	$ 95,000,000
Additions (reductions) from provision for credit loss expense	5,000,000	(18,000,000)
Additions from purchases of PCD mortgage loans on real estate
Balance as of end-of-year	103,000,000	77,000,000
Financing Receivable, Credit Loss, Expense (Reversal)	16,000,000	1,000,000
Accrued investment income excluded from credit losses	52,000,000	49,000,000
Unfunded Loan Commitment [Member]
Schedule of Investments [Line Items]
Financing Receivable, Credit Loss, Expense (Reversal)	1,000,000	0
Commercial [Member]
Schedule of Investments [Line Items]
Balance as of beginning-of-year	83,000,000	78,000,000
Additions (reductions) from provision for credit loss expense		(19,000,000)
Additions from purchases of PCD mortgage loans on real estate
Balance as of end-of-year	83,000,000	59,000,000
Residential [Member]
Schedule of Investments [Line Items]
Balance as of beginning-of-year	15,000,000	17,000,000
Additions (reductions) from provision for credit loss expense	5,000,000	1,000,000
Additions from purchases of PCD mortgage loans on real estate
Balance as of end-of-year	$ 20,000,000	$ 18,000,000