Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Allowance for accounts receivable	$ 96	$ 178
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	4,855,000	4,855,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares issued	40,423,765	40,402,059
Common stock, shares outstanding	37,614,420	37,620,736
Treasury stock, shares	2,809,345	2,781,323
Series A Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	110,000	110,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock Non-Voting [Member]
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0