Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income (loss)	$ (3,597)	$ (1,385)
Adjustments to reconcile net loss to net cash provided by operating activities:
Provision for doubtful accounts	434	391
Depreciation and amortization	6,255	6,232
Deferred income taxes	(1,060)	(336)
Gain (Loss) on Disposition of Property Plant Equipment	145	39
Gain (Loss) on Sale of Derivatives	241	(18)
Compensation expense related to stock-based awards and employee stock purchase plan	1,881	1,874
Foreign Currency Transaction Gain (Loss), Unrealized	697	0
Changes in operating assets and liabilities:
Accounts receivable	10,171	1,794
Inventories	(134)	(2,082)
Prepaid expenses and other assets	(1,002)	(1,679)
Other non-current assets	(1,575)	31
Accounts payable	603	(3,397)
Deferred revenue	824	1,135
Accrued expenses	(4,957)	2,312
Other long-term liabilities	(74)	(7)
Net cash provided by operating activities	8,852	4,904
Cash flows from investing activities:
Capital expenditures	(2,528)	(3,492)
Purchases of marketable securities	(3,780)	(10,649)
Maturities and sales of marketable securities	3,740	7,587
Net cash used in investing activities	(2,568)	(6,554)
Cash flows from financing activities:
Repayments of Long-term loan	2,437	2,437
Repayments of Other Long-term Debt	(674)	(651)
Payments of employee restricted stock withholdings	313	344
Proceeds From Stock Options Exercised and Employee Stock Purchase Plan	119	190
Net cash used in financing activities	(3,305)	(3,242)
Effect of exchange rate changes on cash and cash equivalents	(912)	69
Net increase (decrease) in cash and cash equivalents	2,067	(4,823)
Cash and cash equivalents at beginning of period	22,719	25,289
Cash and cash equivalents at end of period	$ 24,786	$ 20,466