Revenue and Expense - Additional Information (Details) - Parent Company [Member] - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Management fee income	$ 2.3	$ 1.7	$ 1.3
Compensation expense	$ 2.3	$ 1.7	$ 1.3