Allowance for Expected Credit Losses (Details) - Changes in the Allowance for Estimated Uncollectible Reinsurance - USD ($) $ in Millions		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Reinsurance recoverables, allowance for uncollectible reinsurance
Reinsurance recoverables (net of allowance for estimated uncollectible reinsurance), balance, beginning of period		$ 8,350	$ 8,235
Reinsurance recoverables (net of allowance for estimated uncollectible reinsurance), balance, end of period	$ 8,235	8,452	8,350
Reinsurance recoverables, allowance for uncollectible reinsurance [Roll Forward]
Reinsurance recoverables, allowance for uncollectible reinsurance, beginning balance		146	92
Reinsurance recoverables, allowance for estimated uncollectible reinsurance	$ 92	141	146
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13 [Member]
Current period change for estimated uncollectible reinsurance		(5)	1
Write-offs of uncollectible reinsurance recoverables		0	0
Reinsurance recoverables, allowance for uncollectible reinsurance, ending balance	$ 92	$ 141	146
Cumulative Effect, Period of Adoption, Adjustment [Member]
Reinsurance recoverables, allowance for uncollectible reinsurance [Roll Forward]
Reinsurance recoverables, allowance for uncollectible reinsurance, beginning balance			$ 53
Reinsurance recoverables, allowance for estimated uncollectible reinsurance	53			$ 53
Reinsurance recoverables, allowance for uncollectible reinsurance, ending balance	$ 53