Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net loss	$ (11,266)	$ (17,144)	$ (34,034)
Adjustments to reconcile net loss to net cash used for operating activities:
Depreciation and amortization	4,589	5,075	6,877
Gain on sale of dry strip assets and intellectual property		(1,167)	(7,904)
Deferred taxes	1,266	(1,465)	826
Other			186
Stock-based compensation expense	4,812	4,337	3,976
Provision for inventory reserves	1,817	2,562	14,492
Changes in operating assets & liabilities
Accounts receivable	(7,069)	(11,528)	10,478
Inventories	(12,280)	2,209	5,903
Prepaid expenses and other current assets	(1,384)	125	4,386
Accounts payable and other current liabilities	772	7,308	(13,490)
Deferred revenue	2,577	(2,181)	(5,396)
Income taxes	(212)	133	(225)
Other assets and liabilities	333	(3,306)	3,328
Net cash used for operating activities	(16,045)	(15,042)	(10,597)
Cash flows from investing activities
Proceeds from sale of dry strip assets and intellectual property		1,200	8,716
Expenditures for property, plant, and equipment	(896)	(821)	(591)
Decrease (increase) in restricted cash		106	(2)
Net cash (used for) provided by investing activities	(896)	485	8,123
Cash flows from financing activities
Increase in restricted cash		(825)
Financing fees and other expenses	(115)	(560)
Proceeds from exercise of stock options	2,895	1,669	968
Proceeds from Employee Stock Purchase Plan	446	436	331
Proceeds from issuance of Term Loan		15,000
Principal payments on Term Loan	(470)
Net cash provided by financing activities	2,756	15,720	1,299
Effect of exchange rate changes on cash	(1,352)	141	(716)
Net (decrease) increase in cash and cash equivalents	(15,537)	1,304	(1,891)
Cash and cash equivalents at beginning of period	46,290	44,986	46,877
Cash and cash equivalents at end of period	30,753	46,290	44,986
Cash paid for:
Income taxes	931	737	848
Interest paid	$ 832	$ 409