CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 94,250	$ 90,635
Trade accounts and other receivables, net	125,179	103,258
Inventories:
Finished goods	87,218	102,625
Raw materials and supplies	47,042	38,061
Total inventories	134,260	140,686
Prepaid expenses and other current assets	5,442	4,293
Prepaid income taxes	1,888
Deferred income taxes	10,363	11,045
Total current assets	371,382	349,917
Property, plant and equipment:
Land and land improvements	31,163	19,700
Land-use and mineral rights	12,751	9,559
Buildings	72,702	67,866
Machinery and equipment	535,529	530,129
Construction in progress	109,735	39,564
Total	761,880	666,818
Less accumulated depreciation and amortization	283,345	240,586
Net property, plant and equipment	478,535	426,232
Goodwill	12,164	12,164
Intangible and other assets, net	16,870	20,565
Total assets	878,951	808,878
Current liabilities:
Accounts payable	24,570	20,078
Accrued payroll and benefits	13,650	13,986
Accrued freight	6,873	4,925
Accrued utilities	3,577	3,707
Accrued income taxes		727
Other accrued expenses	8,018	7,407
Total current liabilities	56,688	50,830
Deferred income taxes	53,676	44,970
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; 23,080,632 and 23,092,906 shares issued and outstanding at December 31, 2013 and 2012, respectively	231	231
Additional paid-in capital	56,782	57,364
Retained earnings	714,835	657,423
Accumulated other comprehensive loss	(3,261)	(1,940)
Total shareholders' equity	768,587	713,078
Total liabilities and shareholders' equity	$ 878,951	$ 808,878