Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Net cash used in operating activities	$ 3,954	$ 3,734
Investing activities
Purchases of marketable securities	(26,340)	(50,205)
Proceeds from maturity of marketable securities	14,157	9,896
Proceeds from sales of marketable securities	11,492	40,821
Purchases of property and equipment	(1,629)	(1,002)
Decrease (increase) in restricted deposits	455	(327)
Net cash used in investing activities	(1,865)	(817)
Financial activities
Purchase of treasury stock	(11,194)	(12,484)
Issuance of common stock and treasury stock upon exercise of stock options	1,138	514
Net cash used in financing activities	(10,056)	(11,970)
Decrease- in cash and cash equivalents	(7,967)	(9,053)
Erosion- due to exchange rate differences	(85)	(16)
Cash and cash equivalents at the beginning of the period	20,544	23,578
Cash and cash equivalents at the end of the period	$ 12,492	$ 14,509