Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net Income (Loss)	$ 63,787	$ 42,558	$ (28,326)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities
Equity-Based Compensation Expense	111,568	117,991	115,928
Depreciation and Amortization Expense	14,496	9,973	8,143
Amortization of Operating Lease Right-of-Use Assets	18,312
Deferred Taxes	11,509	(7,832)	30,961
Gain on Reversal of Amount Due Pursuant to Tax Receivable Agreement			(1,561)
Other	3,566	708	(759)
Cash Flows Due to Changes in Operating Assets and Liabilities
Accounts Receivable	(11,059)	(36,593)	41,179
Other Assets	(17,612)	(930)	(8,700)
Accrued Compensation and Benefits	29,944	(5,417)	(46,098)
Accounts Payable, Accrued Expenses and Other Liabilities	1,355	(1,602)	(322)
Operating Lease Liabilities	(18,546)
Deferred Rent Liability		(638)	324
Taxes Payable	(2,209)	4,811	867
Deferred Revenue	6,294	(89)	(421)
Net Cash Provided by Operating Activities	211,405	122,940	111,215
Investing Activities
Cash Paid for Acquisition, Net of Cash Received		(61,463)
Purchases of Investments	(11,253)	(22,000)	(57,163)
Proceeds from Sales and Maturities of Investments	10,859	59,176	19,988
Purchases of Furniture, Equipment and Leasehold Improvements	(8,811)	(7,206)	(1,062)
Settlement of Acquisition-Related Escrow	7,485
Net Cash Used in Investing Activities	(1,720)	(31,493)	(38,237)
Financing Activities
Dividends	(4,645)	(4,319)	(3,796)
Proceeds from Revolving Credit Facility	15,000
Payments on Revolving Credit Facility	(15,000)
Proceeds from Term Loan		30,000
Principal Payments on Term Loan	(8,500)
Tax Distributions	(11,428)	(15)	(23,859)
Employee Taxes Paid for Shares Withheld	(9,598)	(22,432)	(4,074)
Cash-Settled Exchanges of Partnership Units	(18,953)	(68,928)	(45,511)
Treasury Stock Purchases	(47,812)	(64,870)	(2,302)
Payments Pursuant to Tax Receivable Agreement	(210)	(10)
Principal Payments on Finance Leases	(145)	(106)	(97)
Net Cash Used in Financing Activities	(101,291)	(130,680)	(79,639)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	1,446	(276)	(151)
Net Increase (Decrease) in Cash and Cash Equivalents	109,840	(39,509)	(6,812)
Cash and Cash Equivalents, Beginning of Period	106,110	145,619	152,431
Cash and Cash Equivalents, End of Period	215,950	106,110	145,619
Supplemental Disclosure of Cash Flows Information
Payments for Income Taxes, Net of Refunds Received	3,843	501	$ 15,106
Payments for Interest	$ 1,386	368
Non-Cash Receipt of Shares		2,254
CamberView
Supplemental Disclosure of Significant Non-Cash Activities
Assets Acquired		150,256
Liabilities Assumed		15,696
Equity Purchase Price Consideration		$ 73,097