Investments (Allowance on available-for-sale securities with credit impairments and PCD assets activity) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Allowance for credit losses:
Balance, beginning of period	$ 1	$ 18
Additions to the allowance for credit losses:
Available-for-sale securities accounted for as PCD assets	9	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	3	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	2	17
Corporate and other bonds
Allowance for credit losses:
Balance, beginning of period	0	11
Additions to the allowance for credit losses:
Available-for-sale securities accounted for as PCD assets	9	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	3	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	1	12
Asset-backed
Allowance for credit losses:
Balance, beginning of period	1	7
Additions to the allowance for credit losses:
Available-for-sale securities accounted for as PCD assets	0	0
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
Additional increases or (decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	0	(2)
Balance, end of period	$ 1	$ 5