Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income (loss)	$ 62,875	$ 108,542
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Bad debt expense	2,808	2,254
Depreciation and amortization	3,216	3,729
Equity-based compensation	97,724	97,505
Deferred tax provision and income tax receivable	(7,111)	10,262
Gain on partial sale of equity method investment		(12,631)
Other	8,509	(4,228)
Changes in assets and liabilities:
Accounts receivable	(23,532)	(44,437)
Accrued and other receivables	(2,589)	(4,408)
Prepaid expenses and other assets	1,190	(2,985)
Deferred compensation	(1,585)	(89)
Compensation payable	(45,715)	(132,164)
Accounts payable, accrued expenses and other liabilities	1,245	(12,373)
Deferred revenue	4,464	(3,089)
Dividends received	1,942	2,848
Net cash provided by (used in) operating activities	103,441	8,736
Cash flows from investing activities
Purchase of investments	(259,965)	(121,590)
Proceeds from sales of investments	252,484	89,859
Notes issued to employees	(200)
Purchase of equipment and leasehold improvements	(31,209)	(5,532)
Proceeds from partial sale of equity method investment		28,264
Net cash provided by (used in) investing activities	(38,890)	(8,999)
Cash flows from financing activities
Dividends and distributions	(122,871)	(178,122)
Proceeds from exercise of stock options	11,923	7,866
Treasury stock purchases	(33,354)	(42,073)
Net cash provided by (used in) financing activities	(144,302)	(212,329)
Effect of exchange rate fluctuations on cash, cash equivalents, and restricted cash	(2,672)	463
Net increase (decrease) in cash, cash equivalents, and restricted cash	(82,423)	(212,129)
Cash, cash equivalents, and restricted cash, beginning of period	168,572	261,771
Cash, cash equivalents, and restricted cash, end of period	86,149	49,642
Cash paid during the period for:
Income taxes	1,914	13,731
Other non-cash activity
Cumulative effect adjustment upon adoption of ASU 2016-13	364
Dividend equivalents issued	17,021	28,688
Class A Partnership Units or other equity converted into Class A Common Stock	5,968	712
Forfeiture of fully-vested Group LP units or other equity units	$ 96	$ 2,397