Contracts Accounted for as Insurance - Deferred Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning of period	$ 119	$ 111	$ 105
Costs deferred during the period	26	24	23
Costs amortized during the period	(14)	(16)	(17)
End of period	$ 131	$ 119	$ 111