CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities:
Net (loss) income	$ (1,461)	$ 3,080
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	3,718	3,086
Stock-based compensation	1,417	1,482
Provision for bad debts	89	310
Loss on disposal of assets	77	64
Provision for excess and obsolete inventory	567	413
Deferred income tax expense	6	165
Income tax benefit from exercise of stock options	0	(65)
Decrease (increase) in:
Accounts receivable	1,722	11,109
Inventories	(2,480)	(1,585)
Prepaid expenses and other current assets	(1,181)	(717)
(Decrease) increase in:
Accounts payable and accrued liabilities	(2,442)	(5,305)
Income taxes payable	(618)	641
Customer deposits	(123)	(635)
Unearned service revenues	430	1,077
Net cash (used in) provided by operating activities	(279)	13,120
Investing activities:
Purchases of property and equipment	(1,745)	(2,057)
Payments for intangible assets	(332)	(322)
Net cash used in investing activities	(2,077)	(2,379)
Financing activities:
Payments on capital leases	(2)	(2)
Income tax benefit from exercise of stock options	0	65
Proceeds from issuance of stock, net	268	452
Net cash provided by financing activities	266	515
Effect of exchange rate changes on cash and cash equivalents	1,779	1,666
(Decrease) increase in cash and cash equivalents	(311)	12,922
Cash and cash equivalents, beginning of period	106,169	107,356
Cash and cash equivalents, end of period	$ 105,858	$ 120,278