Investments (Allowance on available-for-sale securities with credit impairments and PCD assets activity) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Allowance for credit losses:
Balance, beginning of period	$ 22	$ 5	$ 1	$ 18
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	5	0	13	0
Available-for-sale securities accounted for as PCD assets	2	0	22	3
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	0	0	6	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	3	0
Write-offs charged against the allowance	15	0	15	12
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	4	(2)	6	(6)
Balance, end of period	18	3	18	3
Corporate and other bonds
Allowance for credit losses:
Balance, beginning of period	13	0	0	11
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	5	0	6	0
Available-for-sale securities accounted for as PCD assets	2	0	22	0
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	0	0	6	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	3	0
Write-offs charged against the allowance	15	0	15	12
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	0	0	1	1
Balance, end of period	5	0	5	0
Asset-backed
Allowance for credit losses:
Balance, beginning of period	9	5	1	7
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	0	0	7	0
Available-for-sale securities accounted for as PCD assets	0	0	0	3
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	0	0	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	0	0
Write-offs charged against the allowance	0	0	0	0
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	4	(2)	5	(7)
Balance, end of period	$ 13	$ 3	$ 13	$ 3