Investments, Allowance for Credit Losses (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)		Jun. 30, 2020 USD ($)
Investments [Abstract]
Accrued interest receivables on available-for-sale fixed maturity securities	$ 373		$ 373
Allowance for Credit Losses [Roll Forward]
Beginning balance	49		0
Additions to allowance for securities for which credit losses were not previously recorded	22		70
Additions to allowance for available-for-sale securities accounted for as PCD assets	1		2
Reductions for securities sold during the period (realized)	1		6
Reductions for intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis			1
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	(20)		(20)
Total allowance for credit losses	51	[1]	51	[1]
ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			6
Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			6
Corporate and Other Bonds [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	49		0
Additions to allowance for securities for which credit losses were not previously recorded	10		58
Additions to allowance for available-for-sale securities accounted for as PCD assets	1		2
Reductions for securities sold during the period (realized)	1		6
Reductions for intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis			1
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	(20)		(20)
Total allowance for credit losses	39	[1]	39	[1]
Corporate and Other Bonds [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			6
Asset-Backed [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	0		0
Additions to allowance for securities for which credit losses were not previously recorded	12		12
Total allowance for credit losses	$ 12	[1]	$ 12	[1]

[1] On January 1, 2020, the Company adopted ASU 2016-13; see Note 1. The Unrealized OTTI Losses (Gains) column that tracked subsequent valuation changes on securities for which a credit loss had previously been recorded has been replaced with the Allowance for Credit Losses column. Prior period amounts were not adjusted for the adoption of this standard.