CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 56,380	$ 82,936
Restricted cash	1,695	1,012
Short-term investments	6,022	36
Accounts receivable - trade, net of allowance of $31 and $33, respectively	32,028	59,850
Inventories	107,905	75,768
Prepaid income tax	763	1,394
Prepaid expenses and other current assets	10,377	8,701
Total current assets	215,170	229,697
Property, plant and equipment, net	222,545	197,943
Land use rights, net	5,832	804
Intangible assets, net	3,971	4,007
Deferred income tax assets	18,493	12,801
Other assets, net	15,074	7,732
TOTAL ASSETS	481,085	452,984
Current liabilities
Current portion of notes payable and long-term debt	8,275	559
Accounts payable	53,706	43,624
Accrued income taxes		7,422
Accrued liabilities	20,723	19,103
Total current liabilities	82,704	70,708
Notes payable and long-term debt, less current portion	62,896	49,000
TOTAL LIABILITIES	145,600	119,708
Stockholders' equity:
Preferred Stock; 5,000 shares authorized at $0.001 par value; no shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively
Common Stock; 45,000 shares authorized at $0.001 par value; 19,758 and 19,451 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	20	19
Additional paid-in capital	290,070	285,376
Accumulated other comprehensive income	835	9,743
Retained earnings	44,560	38,138
TOTAL STOCKHOLDERS' EQUITY	335,485	333,276
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 481,085	$ 452,984