Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (1,190)	$ (1,957)	$ (3,003)
Adjustments required to reconcile net loss to net cash provided by operating activities:
Depreciation	1,517	1,593	1,781
Equity-based compensation expenses related to employees’ stock options, SARs and RSUs	7,631	6,804	5,861
Capital loss from sale and disposal of property and equipment	9		19
Realized losses from sale of marketable securities, net	73	41	50
Amortization of intangible assets	417	1,700	1,700
Operating lease right-of-use asset amortization expenses	1,347
Change in operating lease liability	(562)
Accrued interest and amortization of premium on marketable securities and short-term deposits	337	601	372
Change in operating assets and liabilities:
Deferred income tax assets and liabilities, net	(2,833)	(2,814)	(459)
Trade receivables, net	(1,916)	(107)	5,728
Other accounts receivable and prepaid expenses	817	(76)	(1,142)
Inventories	2,345	(431)	363
Long-term prepaid expenses and lease deposits	(28)	(159)	(212)
Trade payables	(1,197)	927	(3,893)
Accrued compensation and benefits	2,515	1,598	1,878
Income tax accruals	1,653	180	39
Accrued expenses and other accounts payable	(573)	767	(704)
Accrued severance pay, net	84	(8)	117
Accrued pensions	26	32	18
Net cash provided by operating activities	10,472	8,691	8,513
Cash flows from investing activities:
Purchase of marketable securities	(57,558)	(27,564)	(38,924)
Purchase of short-term deposits	(15,942)	(8,668)	(10,884)
Proceeds from maturity of marketable securities	44,396	20,501	21,499
Proceeds from sales of marketable securities	25,064	5,113	19,226
Proceeds from redemption of short-term deposits	14,420	5,668	8,309
Purchases of property and equipment	(5,638)	(1,181)	(838)
Proceeds from sale of fixed assets	51
Other investing activities	(518)	(104)
Net cash provided by (used in) investing activities	4,275	(6,235)	(1,612)
Cash flows from financing activities:
Issuance of common stock and treasury stock upon exercise of stock options	1,351	738	1,509
Purchase of treasury stock		(12,343)	(4,465)
Net cash provided by (used in) financing activities	1,351	(11,605)	(2,956)
Increase (decrease) in cash and cash equivalents and restricted cash	16,098	(9,149)	3,945
Cash and cash equivalents and restricted cash at the beginning of the year	12,639	21,848	17,822
Cash (erosion) due to exchange rate differences		(60)	81
Cash and cash equivalents and restricted cash at the end of the year	28,737	12,639	21,848
Supplemental disclosures of cash flows information:
Cash and cash equivalent	28,737	12,146	21,324
Restricted cash		493	524
Total cash and cash equivalents and restricted cash	28,737	12,639	21,848
Supplemental disclosures of cash flows activities:
Cash paid for income taxes	(495)	(902)	(219)
Cash received for income taxes	702
Net lease liabilities arising from obtaining right-of-use asset	$ 1,114