Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 128,143	$ 168,243
Investments, at fair value	237,361	194,404
Accounts receivable, net of allowance of $84 and $82 as of June 30, 2017 and December 31, 2016, respectively	55,215	50,668
Goodwill and intangible assets, net of accumulated amortization	63,251	63,443
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	34,643	31,104
Prepaid expenses and other assets	21,058	11,618
Deferred tax assets, net	7,370	8,562
Total assets	547,041	528,042
Liabilities
Accrued employee compensation	23,080	34,783
Income and other tax liabilities	4,686	7,582
Deferred revenue	3,076	2,515
Accounts payable, accrued expenses and other liabilities	14,971	15,149
Total liabilities	45,813	60,029
Commitments and Contingencies (Note 10)
Stockholders' equity
Additional paid-in capital	343,085	342,311
Treasury stock - Common stock voting, at cost, 2,687,979 and 2,562,585 shares as of June 30, 2017 and December 31, 2016, respectively	(141,477)	(117,330)
Retained earnings	310,777	255,140
Accumulated other comprehensive loss	(11,278)	(12,228)
Total stockholders' equity	501,228	468,013
Total liabilities and stockholders' equity	547,041	528,042
Undefined Preferred Stock [Member]
Stockholders' equity
Preferred stock
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock
Voting Common Stock [Member]
Stockholders' equity
Common stock	$ 121	$ 120