Investments - Allowance for Losses for Commercial Mortgage Loans (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Allowance for Loan and Lease Losses [Roll Forward]
Balance as of January 1, 2022	$ 48	$ 14
Credit losses on mortgage loans for which credit losses were not previously recorded	21	36
Initial allowance for credit losses recognized on financial assets accounted for as PCD	0	0
Increase (decrease) on mortgage loans with allowance recorded in previous period	15	(2)
Write-offs	0	0
Recoveries of amounts previously written off	0	0
Balance at March 31, 2022	47	$ 48
Financing Receivable, Nonaccrual, Number Of Loans | loan		0
Financing Receivable, Nonaccrual, Interest Income	0
Commercial Portfolio Segment
Allowance for Loan and Lease Losses [Roll Forward]
Balance as of January 1, 2022	11	$ 67
Credit losses on mortgage loans for which credit losses were not previously recorded	1	1
Accounts Receivable, Sale	0	(7)
Increase (decrease) on mortgage loans with allowance recorded in previous period	(3)	(50)
Provision for expected credit losses	9	11
Write-offs	0	0
Recoveries of amounts previously written off	0	0
Balance at March 31, 2022	$ 9	$ 11
Troubled debt restructuring, number of contracts | loan	0