CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 39,361	$ 91,680
Restricted cash	5,723
Trade accounts and other receivables, net	37,396	23,622
Inventories:
Finished goods	69,613	74,133
Raw materials and supplies	22,848	23,041
Total inventories	92,461	97,174
Prepaid expenses and other current assets	5,346	3,548
Income tax receivable	2,396	1,199
Total current assets	182,683	217,223
Restricted cash	5,543
Property, plant and equipment:
Land and land improvements	45,240	45,530
Land-use and mineral rights	19,696	19,696
Buildings	87,470	87,318
Machinery and equipment	647,694	647,753
Construction in progress	92,935	92,704
Total property, plant and equipment	893,035	893,001
Less accumulated depreciation and amortization	420,777	398,898
Net property, plant and equipment	472,258	494,103
Goodwill	3,500	3,500
Intangible and other assets, net	8,674	8,631
Total assets	672,658	723,457
Current liabilities:
Long-term debt, current portion		13,000
Notes payable	1,246	551
Accounts payable	8,967	7,782
Accrued payroll and benefits	3,233	3,434
Derivative instruments	2,490	1,599
Other accrued expenses	10,707	8,438
Total current liabilities	26,643	34,804
Deferred income taxes	1,602	1,236
Long-term debt, net	48,119	42,404
Notes payable, related parties	25,997	25,000
Other long-term liabilities	4,141	3,443
Shareholders' equity:
Preferred stock, par value $0.01 per share, 5,000 shares authorized, none outstanding
Common stock, par value $0.01 per share, 80,000,000 shares authorized; 27,147,346 and 26,881,066 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	271	269
Additional paid-in capital	123,899	117,192
Retained earnings	475,635	533,435
Accumulated other comprehensive loss	(33,649)	(34,326)
Total shareholders' equity	566,156	616,570
Total liabilities and shareholders' equity	$ 672,658	$ 723,457