Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (1,798)	$ (1,541)
Adjustments to reconcile net loss to net cash flow from operating activities:
Depreciation and amortization	8,304	8,467
Stock-based compensation	2,697	2,574
Other	418	(623)
Changes in operating assets and liabilities:
Accounts receivable	(2,458)	(6,911)
Inventory	(7,302)	(7,848)
Prepaid expenses and other assets	(16)	(7)
Accounts payable	481	4,200
Accrued expenses and other liabilities	(1,417)	(4,579)
Deferred revenues	222	(1,026)
Net cash used in operating activities	(869)	(7,294)
Cash flows from investing activities:
Purchases of property and equipment	(1,092)	(1,605)
Net cash used in investing activities	(1,092)	(1,605)
Cash flows from financing activities:
Issuance of shares under stock incentive plans, net of payroll taxes paid	(268)	4,742
Repayments on loans and lines of credit	(14)	(75)
Repayments on capital leases	(399)	(338)
Net cash (used in) provided by financing activities	(681)	4,329
Foreign exchange effect on cash and cash equivalents	333	393
Decrease in cash and cash equivalents	(2,309)	(4,177)
Cash and cash equivalents, beginning of period	64,928	59,632
Cash and cash equivalents, end of period	$ 62,619	$ 55,455