Investments (Allowance on available-for-sale securities with credit impairments and PCD assets activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Allowance for credit losses:
Balance, beginning of period	$ 1	$ 18
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	17	0
Available-for-sale securities accounted for as PCD assets	22	3
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	6	0
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	8	0
Write-offs charged against the allowance	15	12
Recoveries of amounts previously written off	0	0
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	5	(8)
Balance, end of period	16	1
Corporate and other bonds
Allowance for credit losses:
Balance, beginning of period	0	11
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	10	0
Available-for-sale securities accounted for as PCD assets	22	0
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	6	0
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	8	0
Write-offs charged against the allowance	15	12
Recoveries of amounts previously written off	0	0
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	1	1
Balance, end of period	4	0
Asset-backed
Allowance for credit losses:
Balance, beginning of period	1	7
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	7	0
Available-for-sale securities accounted for as PCD assets	0	3
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	0	0
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	0	0
Write-offs charged against the allowance	0	0
Recoveries of amounts previously written off	0	0
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	4	(9)
Balance, end of period	$ 12	$ 1