Condensed Consolidated Statements Of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net loss	$ (39,050,000)	$ (2,201,000)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	20,630,000	16,921,000
Stock-based compensation expense	5,692,000	14,445,000
Deferred taxes	673,000	(1,162,000)
Amortization of investment, debt and other	158,000	125,000
Gain on sale of assets and other write-offs	(1,623,000)	(18,000)
Gain on foreign currency hedges	(1,501,000)	0
Allowance for doubtful accounts	76,000	(415,000)
Write-down of inventories	7,083,000	1,995,000
Asset impairment charge	275,000	0
Foreign currency remeasurement and other, net	1,576,000	(556,000)
Change in assets and liabilities, net of effects of asset sale:
Accounts receivable	13,755,000	(12,169,000)
Inventories	(36,466,000)	4,518,000
Prepaid expenses and other assets	(12,002,000)	(3,439,000)
Accounts payable	(9,424,000)	12,610,000
Accrued and other liabilities	8,937,000	(3,937,000)
Net cash (used in) provided by operating activities	(41,211,000)	26,717,000
Cash flows from investing activities
Purchase of property, plant and equipment	(41,461,000)	(29,962,000)
Proceeds from sale of property, plant and equipment and other assets	21,806,000	139,000
Purchase of marketable securities	(52,031,000)	(69,520,000)
Proceeds from sale of marketable securities	52,272,000	48,979,000
Proceeds from maturity of marketable securities	6,458,000	15,373,000
Change in restricted cash	1,316,000	(226,000)
Settlement of foreign currency hedges	1,553,000	0
Net cash used in investing activities	(10,087,000)	(35,217,000)
Cash flows from financing activities
Proceeds from exercise of stock options and issuance of stock under ESPP	3,568,000	5,083,000
Tax withholding on restricted stock units	(973,000)	(570,000)
Payments for public stock offering	(117,000)	(25,000)
Proceeds from bank loans, net of debt issuance costs	96,039,000	71,400,000
Repayment of bank loans	(68,270,000)	(72,090,000)
Proceeds from issuance of notes payable	5,842,000	13,144,000
Repayment of notes payable	(9,789,000)	(14,069,000)
Proceeds from government grants	0	608,000
Net cash provided by financing activities	26,300,000	3,481,000
Effect of exchange rates on cash and cash equivalents	1,026,000	556,000
Net decrease in cash and cash equivalents	(23,972,000)	(4,463,000)
Cash and cash equivalents at the beginning of the period	82,500,000	76,088,000
Cash and cash equivalents at the end of the period	58,528,000	71,625,000
Supplemental disclosure of non-cash investing and financing activities:
Decrease (increase) in unpaid property, plant and equipment	6,430,000	(12,494,000)
Asset retirement obligations	2,146,000	0
Unpaid deferred offering costs	$ 0	$ 76,000