CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net income (loss)	$ 10,793	$ 4,283	$ (1,406)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for obsolete inventory	2,832	941	492
Depreciation and amortization	9,424	6,169	3,407
Loss on disposal of assets	78	12	1
Share-based compensation and warrant expense	2,120	2,061	1,069
Unrealized foreign exchange loss	2,462	1,288	362
Changes in operating assets and liabilities:
Accounts receivable	(7,531)	(9,703)	(8,457)
Notes receivable	977	(977)	1,036
Inventory	(37,502)	(16,105)	(7,520)
Other current assets	(2,624)	(745)	(4,622)
Accounts payable	(1,258)	18,947	8,079
Accrued liabilities	5,017	2,359	1,369
Net cash provided by (used in) operating activities	(15,212)	8,530	(6,190)
Investing activities:
Purchase of short-term investments	(175)	(246)	(7,970)
Purchase of property, plant and equipment	(57,080)	(41,129)	(9,600)
Proceeds from disposal of equipment	351	47	0
Deposits and deferred charges	(4,238)	(720)	(43)
Purchase of intangible assets	(478)	(3,340)	(123)
Net cash used in investing activities	(61,620)	(45,388)	(17,736)
Financing activities:
Proceeds from issuance of notes payable and long-term debt	16,944	8,150	2,851
Principal payments of long-term debt and notes payable	(2,413)	(8,076)	(285)
Proceeds from line of credit borrowings	144,386	53,658	23,192
Repayments of line of credit borrowings	(121,386)	(50,733)	(23,008)
Proceeds from bank acceptance payable	8,257	5,925	6,778
Repayments of bank acceptance payable	(6,361)	(6,986)	(6,026)
Repayments of note payable	(1,000)	(1,000)	0
Decrease (increase) in restricted cash	(4,419)	266	(249)
Exercise of stock options	452	365	173
Exercise of warrants	0	0	494
Proceeds from common stock offering, net	38,648	45,681	31,448
Other	6	0	0
Net cash provided by financing activities	73,114	47,250	35,368
Effect of exchange rate changes on cash	(383)	(223)	(159)
Net increase (decrease) in cash	(4,101)	10,169	11,283
Cash and cash equivalents at beginning of year	32,175	22,006	10,723
Cash and cash equivalents at end of year	28,074	32,175	22,006
Supplemental disclosure of cash flow information:
Interest	1,070	329	1,133
Income taxes	650	148	1
Non-cash investing and financing activities:
Purchase of intangible assets with notes payable	$ 0	$ 3,000	$ 0