Additional Information - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Commitments to fund credit facilities and limited partnerships	$ 499
Retirement and employee savings plan expense	$ 61	$ 41	$ 39