Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Consolidated net income	$ 585	$ 7,373
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation and amortization	5,244	5,401
Stock-based compensation expense	670	839
Deferred income taxes	(222)	280
(Decrease) increase in long-term deferred revenue	(72)	420
Excess tax benefit of stock-based compensation	(52)	(44)
(Gain) loss on disposal of equipment	(33)	1
Decrease in long-term income taxes payable	(18)
Credit gain on available for sale securities	(4)	(367)
Change in current assets and liabilities, net	6,790	3,195
Net cash provided by operating activities	12,888	17,098
Investing activities:
Additions to property, plant and equipment	(2,785)	(5,035)
Sales and maturities of investments	450	8,260
Purchases of investments	(270)	(270)
Proceeds from sale of equipment	33	4
Decrease (increase) in other assets	11	(10)
Net cash (used in) provided by investing activities	(2,561)	2,949
Financing activities:
Excess tax benefit of stock-based compensation	52	44
Proceeds from issuance of Common Stock	8	418
Net cash provided by financing activities	60	462
Effect of foreign exchange rates on cash	(51)	(9)
Net increase in cash and cash equivalents	10,336	20,500
Cash and cash equivalents at beginning of period	71,908	49,279
Cash and cash equivalents at end of period	$ 82,244	$ 69,779