CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 17,028	$ 13,100	$ 6,267
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation	2,014	1,399	1,058
Amortization of intangible assets	1,236	1,236	1,298
Equity-based compensation	8,693	6,236	4,015
Realized loss, net on sale of available-for-sale marketable securities		9	78
Amortization of premiums on available-for-sale marketable securities	1,179	1,064	1,111
Unrealized foreign exchange (gain) loss, net	(42)	75	237
Changes in operating assets and liabilities:
Trade receivables	(1,446)	(10,966)	4,279
Prepaid expenses and other assets	(2,478)	(622)	(136)
Accrued interest on bank deposits	151	(195)	(318)
Deferred tax, net	(1,375)	(613)	(1,213)
Trade payables	(184)	(190)	(161)
Deferred revenues	(1,859)	3,495	1,082
Accrued expenses and other payables	1,259	(277)	(158)
Accretion of contingent consideration			97
Accrued payroll and related benefits	1,807	(94)	1,679
Income taxes payable	(1,493)	668	93
Excess tax benefit from equity-based compensation			(112)
Accrued severance pay, net	(21)	134	184
Net cash provided by operating activities	24,469	14,459	19,380
Cash flows from investing activities:
Purchase of property and equipment	(4,135)	(2,387)	(2,184)
Investment in bank deposits	(47,027)	(41,476)	(53,328)
Proceeds from bank deposits	44,450	37,594	47,451
Investment in available-for-sale marketable securities	(54,882)	(43,537)	(29,800)
Proceeds from maturity of available-for-sale marketable securities	9,296	8,022	4,392
Proceeds from sale of available-for-sale marketable securities	23,512	20,754	23,713
Proceeds from realization of investment in other company			111
Net cash used in investing activities	(28,786)	(21,030)	(9,645)
Cash flows from financing activities:
Payment of contingent consideration			(3,700)
Purchase of Treasury Stock		(3,417)	(10,078)
Proceeds from exercise of stock-based awards	7,487	9,615	6,713
Excess tax benefit from equity-based compensation			112
Net cash provided by (used in) financing activities	7,487	6,198	(6,953)
Effect of exchange rate changes on cash and cash equivalents	168	(135)	(39)
Increase (decrease) in cash and cash equivalents	3,338	(508)	2,743
Cash and cash equivalents at the beginning of the year	18,401	18,909	16,166
Cash and cash equivalents at the end of the year	21,739	18,401	18,909
Supplemental information of cash-flows activities:
Income and withholding taxes	$ 5,203	3,287	$ 2,185
Property and equipment purchases incurred but unpaid at period end		$ 86