Investments - Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Accrued interest receivables on available-for-sale fixed maturity securities	$ 437	$ 407	$ 435
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	16	1
Available-for-sale securities accounted for as PCD assets	0	9
Securities sold during the period (realized)	0	6
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	1
Write-offs charged against the allowance		3
Additional increases to the allowance for credit losses on securities that had an allowance recorded in a previous period	5	1
Ending balance	20	2
Corporate bonds and other
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	4	0
Available-for-sale securities accounted for as PCD assets		9
Securities sold during the period (realized)		6
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis	1
Write-offs charged against the allowance		3
Additional increases to the allowance for credit losses on securities that had an allowance recorded in a previous period		1
Ending balance	3	1
Asset-backed
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	12	1
Available-for-sale securities accounted for as PCD assets
Securities sold during the period (realized)
Intent to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis
Write-offs charged against the allowance
Additional increases to the allowance for credit losses on securities that had an allowance recorded in a previous period	5
Ending balance	$ 17	$ 1