CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (8,949)	$ (1,915)
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	5,674	5,815
(Recovery) provision for doubtful accounts	57	(110)
Stock-based compensation expense	703	1,411
Non-cash interest expense	3,546	3,131
Unrealized foreign currency transaction losses	1,323	1,722
Benefit for deferred taxes	(2)	(374)
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	8,596	14
Inventories	(482)	1,573
Prepaid expenses and other current assets	(396)	(5,850)
Accounts payable	(2,112)	2,388
Accrued expenses, compensation and benefits and other liabilities	(1,355)	(1,773)
Income taxes payable	190	164
Deferred revenues	(1,423)	(2,662)
Net cash provided by (used in) operating activities	5,370	3,534
Cash flows from investing activities:
Purchases of property and equipment	(2,080)	(1,729)
Increase in other long-term assets	(8)	(7)
Net cash used in investing activities	(2,088)	(1,736)
Cash flows from financing activities:
Repayment of debt	(3,212)	(1,250)
Proceeds from the issuance of common stock under employee stock plans	6	2
Common stock repurchases for tax withholdings for net settlement of equity awards	(497)	(372)
Net cash (used in) provided by financing activities	(3,703)	(1,620)
Effect of exchange rate changes on cash and cash equivalents	(5)	188
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(426)	366
Cash and cash equivalents at beginning of period	57,223
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	60,007	50,314
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents at end of period	48,016	47,014
Restricted Cash, Current	8,500	0
Restricted Cash, Noncurrent	3,491	3,300
Cash paid for income taxes, net of refunds	(2,469)	19
Cash paid for interest	$ 1,919	$ 1,665