Investments (Changes In Allowance For Credit Losses On AFS) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance as of beginning-of-year	$ 13
Balance as of end of-year	14		$ 13
Accrued interest receivable on fixed maturity AFS securities	1,100		1,000
Fixed Maturity AFS Securities [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance as of beginning-of-year	13
Additions for securities for which credit losses were not previously recognized		20
Additions from purchases of PCD debt securities
Additions (reductions) for securities for which credit losses were previously recognized	1
Balance as of end of-year	14	20	13
Fixed Maturity AFS Securities [Member] | Corporate Bonds [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance as of beginning-of-year	12
Additions for securities for which credit losses were not previously recognized		20
Additions from purchases of PCD debt securities
Additions (reductions) for securities for which credit losses were previously recognized	1
Balance as of end of-year	13	20	12
Fixed Maturity AFS Securities [Member] | RMBS [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance as of beginning-of-year	1
Additions from purchases of PCD debt securities
Balance as of end of-year	1		1
Fixed Maturity AFS Securities [Member] | ABS [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance as of beginning-of-year
Additions from purchases of PCD debt securities