Investments, Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Investments [Abstract]
Accrued interest receivables on available-for-sale fixed maturity securities	$ 374	$ 373	$ 374	$ 373	$ 371
Allowance for Credit Losses [Roll Forward]
Beginning balance	43	49	40	0
Additions to allowance for securities for which credit losses were not previously recorded		22	14	70
Additions to allowance for available-for-sale securities accounted for as PCD assets	4	1	6	2
Reductions for securities sold during the period (realized)		1	6	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 (decrease) to the allowance for credit losses on securities that had an allowance recorded in a previous period	(2)	(20)	(9)	(20)
Total allowance for credit losses	45	51	45	51
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	27	49	23	0
Additions to allowance for securities for which credit losses were not previously recorded		10	14	58
Additions to allowance for available-for-sale securities accounted for as PCD assets		1	2	2
Reductions for securities sold during the period (realized)		1	6	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 (decrease) to the allowance for credit losses on securities that had an allowance recorded in a previous period	(3)	(20)	(9)	(20)
Total allowance for credit losses	24	39	24	39
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	16	0	17	0
Additions to allowance for securities for which credit losses were not previously recorded		12		12
Additions to allowance for available-for-sale securities accounted for as PCD assets	4		4
Additional increases or (decrease) to the allowance for credit losses on securities that had an allowance recorded in a previous period	1
Total allowance for credit losses	$ 21	$ 12	$ 21	$ 12