Condensed Consolidated Statements Of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Net cash provided by operating activities	$ 567	$ 476
Investing activities
Purchase of marketable securities	(37,296)	(39,336)
Proceeds from maturity of marketable securities	7,135	9,242
Proceeds from sales of marketable securities	31,989	22,961
Purchases of property and equipment	(698)	(710)
Net cash provided by (used in) investing activities	1,130	(7,843)
Financing activities
Purchase of treasury stock	(7,895)
Issuance of treasury stock for cash upon exercise of stock options	442	1,223
Net cash provided by (used in) financing activities	(7,453)	1,223
Decrease in cash and cash equivalents	(5,756)	(6,144)
Cash erosion due to exchange rate differences	(9)	(1)
Cash and cash equivalents at the beginning of the period	23,578	21,684
Cash and cash equivalents at the end of the period	$ 17,813	$ 15,539