Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net Income	$ 44,468	$ 43,796
Adjustments to Reconcile Net Income to Net Cash Used in Operating Activities
Equity-Based Compensation Expense	59,069	29,948
Depreciation and Amortization Expense	4,307	3,834
Amortization of Operating Lease Right-of-Use Assets	5,362	4,780
Provision for Credit Losses	1,464	(192)
Other	(1,836)	(1,414)
Cash Flows Due to Changes in Operating Assets and Liabilities
Accounts Receivable	(64,972)	(41,087)
Other Assets	(25,721)	(4,236)
Accrued Compensation and Benefits	(57,744)	(177,771)
Accounts Payable, Accrued Expenses and Other Liabilities	(1,862)	(102)
Operating Lease Liabilities	(5,640)	(5,351)
Taxes Payable	(889)	(1,109)
Deferred Revenue	1,755	(856)
Net Cash Used in Operating Activities	(42,239)	(149,760)
Investing Activities
Purchases of Investments	(19,979)	(97,638)
Proceeds from Sales and Maturities of Investments		162,813
Purchases of Furniture, Equipment and Leasehold Improvements	(806)	(43)
Net Cash Provided by (Used in) Investing Activities	(20,785)	65,132
Financing Activities
Dividends	(6,268)	(1,270)
Proceeds from Revolving Credit Facility	42,000	15,000
Payments on Revolving Credit Facility	(17,000)	(15,000)
Employee Taxes Paid for Shares Withheld	(15,367)	(20,415)
Cash-Settled Exchanges of Partnership Units	(6,559)	(48,478)
Treasury Stock Purchases	(56,569)	(45,896)
Payments Pursuant to Tax Receivable Agreement		(1,165)
Net Cash Used in Financing Activities	(59,763)	(117,224)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	(1,887)	1,943
Net Decrease in Cash and Cash Equivalents	(124,674)	(199,909)
Cash and Cash Equivalents, Beginning of Period	200,481	299,513
Cash and Cash Equivalents, End of Period	75,807	99,604
Supplemental Disclosure of Cash Flows Information
Payments for Income Taxes, Net of Refunds Received	$ 2,071	4,458
Non-Cash Receipt of Shares		$ 1,125