Investments (Rollforward of the Allowance for Credit Losses for Fixed Maturity Securities by Sector (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	$ 0
Allowance on securities where credit losses were not previously recorded	4
Reductions for securities sold	(1)
Change in allowance on securities with an allowance recorded in a previous period	(1)
Write-offs charged against allowance	(4)
Fixed maturity securities, allowance for credit losses, end of year	2
U.S. Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	0
Allowance on securities where credit losses were not previously recorded	3
Reductions for securities sold	(1)
Change in allowance on securities with an allowance recorded in a previous period	0
Write-offs charged against allowance	(3)
Fixed maturity securities, allowance for credit losses, end of year	2
Foreign Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	0
Allowance on securities where credit losses were not previously recorded	1
Reductions for securities sold	0
Change in allowance on securities with an allowance recorded in a previous period	(1)
Write-offs charged against allowance	(1)
Fixed maturity securities, allowance for credit losses, end of year	0
Cumulative Effect, Adjusted Balance
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	4
Cumulative Effect, Adjusted Balance | U.S. Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	3
Cumulative Effect, Adjusted Balance | Foreign Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Fixed maturity securities, allowance for credit losses, beginning of year	$ 1