Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ (1,957)	$ (3,003)	$ 4,813
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation	1,593	1,781	1,704
Equity-based compensation expenses related to employees’ stock options, SARs and RSUs	6,804	5,861	5,088
Capital loss from sale and disposal of property and equipment		19	10
Realized losses from sale of marketable securities, net	41	50	17
Amortization of intangible assets	1,700	1,700	1,457
Accrued interest and amortization of premium on marketable securities and short-term deposits	601	372	610
Change in operating assets and liabilities:
Deferred income tax assets and liabilities, net	(2,814)	(459)	320
Trade receivables, net	(107)	5,728	168
Other accounts receivable and prepaid expenses	(76)	(1,142)	953
Inventories	(431)	363	1,702
Long-term prepaid expenses and lease deposits	(159)	(212)	(166)
Trade payables	927	(3,893)	(575)
Accrued compensation and benefits	1,598	1,878	2,566
Income tax accruals	180	39	(724)
Accrued expenses and other accounts payable	767	(704)	(1,379)
Accrued severance pay, net	(8)	117	(91)
Accrued pensions	32	18	42
Net cash provided by operating activities	8,691	8,513	16,515
Cash flows from investing activities:
Purchase of marketable securities	(27,564)	(38,924)	(47,934)
Purchase of short-term deposits	(8,668)	(10,884)	(7,601)
Proceeds from maturity of marketable securities	20,501	21,499	35,090
Proceeds from sales of marketable securities	5,113	19,226	14,277
Proceeds from redemption of short-term deposits	5,668	8,309	5,601
Purchases of property and equipment	(1,181)	(838)	(2,103)
Other investing activities	(104)
Acquisition of initially consolidated subsidiary (1)			(494)
Proceeds from sale of fixed assets			9
Net cash used in investing activities	(6,235)	(1,612)	(3,155)
Cash flows from financing activities:
Issuance of common stock and treasury stock upon exercise of stock options	738	1,509	1,457
Repayment of short-term loan			(168)
Purchase of treasury stock	(12,343)	(4,465)	(10,727)
Net cash used in financing activities	(11,605)	(2,956)	(9,438)
Increase (decrease) in cash and cash equivalents and restricted cash	(9,149)	3,945	3,922
Cash and cash equivalents and restricted cash at the beginning of the year	21,848	17,822	13,872
Cash (erosion) due to exchange rate differences	(60)	81	28
Cash and cash equivalents and restricted cash at the end of the year	12,639	21,848	17,822
Taxes on income	$ 902	$ 219	$ 1,018