Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net loss	$ (16,797)	$ (10,474)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for losses on accounts receivable	35	0
Lower of cost or market reserve adjustment to inventory	1,648	2,287
Depreciation and amortization	6,031	5,948
Amortization of debt issuance costs	220	243
Deferred income taxes, net	(1,877)	(2,474)
Loss on disposal of assets	0	9
Share-based compensation	3,238	2,942
Unrealized foreign exchange gain	(103)	(249)
Changes in operating assets and liabilities:
Accounts receivable, trade	8,836	(1,589)
Notes receivable	0	(79)
Prepaid income tax	(151)	(224)
Inventories	(4,533)	7,304
Other current assets	(1,085)	3,670
Operating right of use asset	63	245
Accounts payable	3,408	(1,579)
Accrued liabilities	(7,117)	(5,698)
Lease liability	(62)	(242)
Net cash provided by (used in) operating activities	(8,246)	40
Investing activities:
Purchase of property, plant and equipment	(2,787)	(12,812)
Proceeds from disposal of equipment	52	1
Deposits and prepaid for equipment	(353)	3,931
Purchase of intangible assets	(112)	(155)
Net cash used in investing activities	(3,200)	(9,035)
Financing activities:
Proceeds from issuance of notes payable and long-term debt, net of debt issuance costs	0	6,488
Principal payments of long-term debt and notes payable	(1,108)	(40,132)
Proceeds from line of credit borrowings	24,916	10,859
Repayments of line of credit borrowings	(20,000)	(25,747)
Proceeds from bank acceptance payable	7,195	2,382
Repayments of bank acceptance payable	(3,798)	(1,917)
Proceeds from issuance of convertible senior notes, net of debt issuance costs	(13)	76,378
Principal payments of financing lease	(4)	0
Exercise of stock options	0	7
Payments of tax withholding on behalf of employees related to share-based compensation	(259)	(299)
Proceeds from common stock offering, net	(75)	0
Net cash provided by financing activities	6,854	28,019
Effect of exchange rate changes on cash	81	431
Net increase (decrease) in cash, cash equivalents and restricted cash	(4,511)	19,455
Cash, cash equivalents and restricted cash at beginning of period	67,028	58,004
Cash, cash equivalents and restricted cash at end of period	62,517	77,459
Supplemental disclosure of cash flow information:
Interest, net of amounts capitalized	2,237	421
Income taxes	(21)	224
Non-cash investing and financing activities:
Net change in accounts payable related to property and equipment additions	75	(2,168)
Net change in deposits and prepaid for equipment related to property and equipment additions	$ 304	$ 0