CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net income (loss)	$ 68,235	$ 17,009
Adjustments to reconcile net income to net cash provided by operating activities:
Lower of cost or market adjustment to inventory	1,365	2,799
Depreciation and amortization	14,332	9,926
Deferred income taxes, net	(2,495)	(11,856)
Loss on disposal of assets	51	89
Share-based compensation	5,849	2,830
Unrealized foreign exchange loss	308	3,509
Changes in operating assets and liabilities:
Accounts receivable, trade	(23,261)	(5,412)
Inventories	(21,113)	9,423
Other current assets	(6,062)	3,450
Accounts payable	14,618	3,886
Accrued income taxes	4,360	177
Accrued liabilities	1,927	(444)
Net cash provided by operating activities	57,498	28,368
Investing activities:
Maturities of short-term investments	8	7,749
Change in restricted cash for construction in progress	8	(847)
Purchase of property, plant and equipment	(46,529)	(40,333)
Proceeds from disposal of equipment	171	1,306
Deposits and prepaid charges	(2,369)	659
Purchase of intangible assets	(407)	(440)
Net cash used in investing activities	(49,118)	(31,906)
Financing activities:
Proceeds from issuance notes payable and long-term debt		28,858
Principal payments of long-term debt and notes payable	(38,300)	(3,995)
Proceeds from line of credit borrowings	36,000	115,798
Repayments of line of credit borrowings		(114,542)
Proceeds from bank acceptance payable		5,850
Repayments of bank acceptance payable	(307)	(5,531)
Repayments of notes payable		(750)
Exercise of stock options	1,399	480
Payments of tax withholding on behalf of employees related to share-based compensation	(8,490)
Proceeds from common stock offering, net	21,572
Net cash provided by financing activities	11,874	26,168
Effect of exchange rate changes on cash	(208)	4,769
Net increase in cash, cash equivalents and restricted cash	20,046	27,399
Cash and cash equivalents at beginning of period	50,224	28,074
Cash, cash equivalents and restricted cash, at beginning of period	51,956	32,793
Cash, cash equivalents and restricted cash, at end of period	72,002	60,192
Cash and cash equivalents at end of period	70,930	55,907
Cash paid for:
Interest	730	1,277
Income taxes	4,992	$ (12)
Non-cash investing and financing activities:
Net change in accounts payable related to property and equipment additions	$ (1,091)