Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 320,527	$ 246,322
Investments, at fair value	235,625	240,105
Accounts receivable, net of allowance of $146 and $80 as of September 30, 2019 and December 31, 2018, respectively	72,812	57,535
Goodwill and intangible assets, net of accumulated amortization	62,387	62,675
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	66,531	63,010
Operating lease right-of-use assets	75,390
Prepaid expenses and other assets	18,591	22,468
Deferred tax assets, net	3,163	3,424
Total assets	855,026	695,539
Liabilities
Accrued employee compensation	35,082	39,053
Income and other tax liabilities	13,274	16,432
Deferred revenue	3,731	2,810
Accounts payable, accrued expenses and other liabilities	16,285	29,366
Operating lease liabilities	92,031
Total liabilities	160,403	87,661
Commitments and Contingencies (Note 11)
Stockholders' equity
Common stock	122	122
Additional paid-in capital	343,543	341,860
Treasury stock - Common stock voting, at cost, 2,941,159 and 2,900,432 shares as of September 30, 2019 and December 31, 2018, respectively	(196,402)	(184,962)
Retained earnings	560,164	463,252
Accumulated other comprehensive loss	(12,804)	(12,394)
Total stockholders' equity	694,623	607,878
Total liabilities and stockholders' equity	855,026	695,539
Undefined Preferred Stock [Member]
Stockholders' equity
Preferred stock
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock