Summary of Significant Accounting Policies - Company's Income from Investments Held in Employee Deferred Compensation Trusts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Dividend income	$ 23,719	$ 8,322	$ 10,425
Realized and unrealized gains	37,359	66,866	44,492
Income from investments held in employee deferred compensation trusts	$ 61,078	$ 75,188	$ 54,917