Investments (Allowance on available-for-sale securities with credit impairments and PCD assets activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Allowance for credit losses:
Balance, beginning of period	$ 16	$ 1
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	27	17
Available-for-sale securities accounted for as PCD assets	4	22
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	4	6
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	1	8
Write-offs charged against the allowance	9	15
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	12	5
Balance, end of period	45	16
Corporate and other bonds
Allowance for credit losses:
Balance, beginning of period	4	0
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	9	10
Available-for-sale securities accounted for as PCD assets	4	22
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	3	6
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	1	8
Write-offs charged against the allowance	0	15
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	0	1
Balance, end of period	13	4
Asset-backed
Allowance for credit losses:
Balance, beginning of period	12	1
Additions to the allowance for credit losses:
Securities for which credit losses were not previously recorded	18	7
Available-for-sale securities accounted for as PCD assets	0	0
Reductions to the allowance for credit losses:
Securities sold during the period (realized)	1	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	9	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	12	4
Balance, end of period	$ 32	$ 12