CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 45,681	$ 68,169
Restricted cash	5,408	6,935
Trade accounts and other receivables, net	45,051	37,705
Inventories:
Finished goods	55,519	59,519
Raw materials and supplies	21,962	19,480
Total inventories	77,481	78,999
Prepaid expenses and other current assets	5,877	3,989
Total current assets	179,498	195,797
Restricted cash	3,857	3,281
Income tax receivable	2,292	2,389
Property, plant and equipment:
Land and land improvements	41,590	41,590
Land-use and mineral rights	19,696	19,696
Buildings	72,443	72,427
Machinery and equipment	454,826	455,863
Construction in progress	36,312	36,138
Total property, plant and equipment	624,867	625,714
Less accumulated depreciation and amortization	317,185	301,528
Net property, plant and equipment	307,682	324,186
Goodwill	3,500	3,500
Intangible and other assets, net	7,128	11,445
Total assets	503,957	540,598
Current liabilities:
Accounts payable	18,075	19,417
Accrued payroll and benefits	5,383	6,056
Accrued freight	1,422	2,292
Accrued utilities	1,501	1,552
Derivative instruments	1,189	2,537
Notes payable, related parties	27,040
Other current liabilities	9,058	10,577
Total current liabilities	63,668	42,431
Deferred income taxes	234	230
Long-term debt, net	61,039	60,698
Notes payable, related parties		27,040
Other long-term liabilities	5,863	4,434
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; 27,743,512 and 27,133,614 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	278	271
Additional paid-in capital	130,600	125,715
Retained earnings	242,275	279,779
Total shareholders' equity	373,153	405,765
Total liabilities and shareholders' equity	$ 503,957	$ 540,598