CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 106,584	$ 24,298
Trade accounts and other receivables, net	69,047	132,573
Inventories:
Finished goods	89,893	106,941
Raw materials and supplies	26,430	37,502
Total inventories	116,323	144,443
Prepaid expenses and other current assets	6,164	5,241
Prepaid income taxes	2,067	19,708
Deferred income taxes	37,012	11,348
Total current assets	337,197	337,611
Property, plant and equipment:
Land and land improvements	42,748	40,921
Land-use and mineral rights	19,877	19,877
Buildings	76,725	74,911
Machinery and equipment	634,101	627,517
Construction in progress	129,135	109,378
Total	902,586	872,604
Less accumulated depreciation and amortization	328,120	303,888
Net property, plant and equipment	574,466	568,716
Goodwill	12,164	12,164
Intangible and other assets, net	20,872	15,735
Total assets	944,699	934,226
Current liabilities:
Bank borrowings	95,000	25,000
Accounts payable	13,334	22,922
Accrued payroll and benefits	5,045	12,466
Accrued freight	2,310	5,925
Accrued utilities	1,602	3,714
Derivative instruments	5,941
Other accrued expenses	10,269	7,388
Total current liabilities	133,501	77,415
Deferred income taxes	82,905	$ 80,754
Derivative instruments	$ 5,017
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; 23,293,541 and 23,092,674 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	$ 233	$ 231
Additional paid-in capital	62,116	59,297
Retained earnings	683,333	739,498
Accumulated other comprehensive loss	(22,406)	(22,969)
Total shareholders' equity	723,276	776,057
Total liabilities and shareholders' equity	$ 944,699	$ 934,226