Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements Of Cash Flows [Abstract]
Net cash used in operating activities	$ (526)	$ (354)
Investing activities
Purchases of marketable securities	(8,627)	(18,639)
Purchases of deposits	(27)	(3,000)
Proceeds from maturity of marketable securities	5,930	15,640
Proceeds from maturity of deposits	3,000	10,000
Proceeds from sales of marketable securities	5,068	959
Purchases of property and equipment	(281)	(765)
Net cash provided by investing activities	5,063	4,195
Financial activities
Purchase of treasury stock	(3,968)	(1,030)
Issuance of common stock and treasury stock for cash upon exercise of options and stock appreciation rights		172
Net cash used in financing activities	(3,968)	(858)
Increase in cash and cash equivalents	569	2,983
Cash erosion due to exchange rate differences	5	(60)
Cash and cash equivalents at the beginning of the period	18,109	33,912
Cash and cash equivalents at the end of the period	$ 18,683	$ 36,835