Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income (loss)	$ (2,379)	$ 28	$ 574
Adjustments required to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	3,233	3,104	2,915
Amortization of intangible assets	2,588	2,165	1,242
Equity-based compensation	13,636	10,718	10,367
Realized loss, net on sale of available-for-sale marketable securities	6	28	67
Amortization of premiums on available-for-sale marketable securities	444	554	773
Unrealized foreign exchange (gain) loss, net	(591)	249	155
Revaluation of investment in non-marketable equity securities	0	(0)	870
Changes in operating assets and liabilities:
Trade receivables, net	(2,917)	(2,151)	(463)
Prepaid expenses and other assets	(559)	(4,170)	(3,855)
Operating lease right-of-use assets	2,014	(1,281)	0
Accrued interest on bank deposits	1,186	(161)	(557)
Deferred taxes, net	(335)	(3,594)	(2,187)
Trade payables	186	53	226
Deferred revenues	(1,208)	85	(806)
Accrued expenses and other payables	133	(131)	(493)
Accrued payroll and related benefits	1,803	3,056	(527)
Operating lease liability	(2,183)	1,166	0
Income taxes payable	143	(53)	96
Accrued severance pay, net	(37)	9	215
Net cash provided by operating activities	15,163	9,674	8,612
Cash flows from investing activities:
Acquisition of business combination	0	(11,000)	0
Purchase of property and equipment	(2,935)	(3,461)	(3,319)
Purchase of intangible assets	0	(7,364)	(1,960)
Investment in bank deposits	(43,893)	(39,346)	(21,596)
Proceeds from bank deposits	55,393	45,435	32,892
Investment in available-for-sale marketable securities	(56,011)	(27,184)	(19,666)
Proceeds from maturity of available-for-sale marketable securities	21,956	3,888	10,122
Proceeds from sale of available-for-sale marketable securities	10,272	36,589	13,354
Net cash provided by (used in) investing activities	(15,218)	(2,443)	9,827
Cash flows from financing activities:
Purchase of treasury stock	(4,780)	(9,113)	(20,008)
Payment of contingent consideration liability	(204)	0	0
Proceeds from exercise of stock-based awards	2,871	2,437	2,249
Net cash used in financing activities	(2,113)	(6,676)	(17,759)
Effect of exchange rate changes on cash and cash equivalents	508	(12)	(159)
Increase (decrease) in cash and cash equivalents	(1,660)	543	521
Cash and cash equivalents at the beginning of the year	22,803	22,260	21,739
Cash and cash equivalents at the end of the year	21,143	22,803	22,260
Supplemental information of cash-flows activities:
Income and withholding taxes	4,727	5,063	4,294
Cumulative effect of adoption of new accounting standard	0	0	8,555
Property and equipment purchases incurred but unpaid at period end	5	21	14
Intangible assets purchased but unpaid at period end	0	0	750
Right-of-use assets obtained in the exchange for operating lease liabilities	$ 6,787	$ 2,493	$ 0