Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income (loss)	$ (10,251)	$ (14,678)	$ (27,581)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	17,256	18,478	20,240
Inventory valuation allowance and adverse purch commitment charges	4,212	3,278	2,862
Deferred income taxes	124	106	3,106
Stock-based compensation expense	3,797	3,952	4,097
Other	(815)	(217)	119
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	22,609	(17,121)	(2,262)
Other receivables	7,110	(5,040)	(3,689)
Inventories and deferred cost of sales	4,890	(13,801)	4,313
Accounts payable	(22,805)	9,853	(1,534)
Accrued wages and bonuses	(789)	2,043	(538)
Accrued restructuring	772	(89)	(2,006)
Deferred revenue	(14,967)	16,682	(1,875)
Other	(1,334)	1,611	(2,049)
Net cash provided by (used in) operating activities	9,809	5,057	(6,797)
Cash flows from investing activities:
Capital expenditures	(4,931)	(2,224)	(2,196)
Net cash used in investing activities	(4,931)	(2,224)	(2,196)
Cash flows from financing activities:
Payments on line of credit	98,000	13,500	0
Payments on line of credit	(88,000)	(8,500)	(5,000)
Repayment of convertible subordinated notes	0	(18,000)	0
Net resettlement of restricted shares	1,040	331	21,186
Net resettlement of restricted shares	(3,287)	(142)	(629)
Other financing activities	(279)	0	(253)
Net cash provided by (used in) financing activities	7,474	(12,811)	15,304
Effect of exchange rate changes on cash	(29)	(500)	(551)
Net increase (decrease) in cash and cash equivalents	12,323	(10,478)	5,760
Cash and cash equivalents, beginning of period	20,764	31,242	25,482
Cash and cash equivalents, end of period	33,087	20,764	31,242
Supplemental disclosure of cash flow information:
Interest	483	835	1,207
Income taxes	$ 1,349	$ 1,289	$ 1,532