CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 10,259	$ 14,163
Accounts receivable, net	380,951	387,530
Inventories	134,170	140,867
Deferred income taxes	7,662	5,777
Income taxes receivable		4,234
Prepaid expenses	8,056	10,762
Other current assets	5,294	4,494
Total current assets	546,392	567,827
Property, plant and equipment, net	739,624	756,326
Goodwill	24,093	24,093
Other assets	18,873	18,917
Total assets	1,328,982	1,367,163
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	108,286	109,846
Accrued payroll and related expenses	28,800	32,053
Accrued insurance expenses	6,321	6,152
Accrued state, local and other taxes	7,932	7,326
Income taxes payable	10,111	6,428
Other accrued expenses	1,098	2,706
Total current liabilities	162,548	164,511
Long-term accrued insurance expenses	11,005	10,400
Notes payable to banks	67,200	107,000
Long-term pension liabilities	27,066	26,543
Deferred income taxes	141,382	155,007
Other long-term liabilities	2,634	4,470
Total liabilities	411,835	467,931
Common stock	21,936	22,014
Retained earnings	909,867	891,464
Accumulated other comprehensive loss	(14,656)	(14,246)
Total stockholders' equity	917,147	899,232
Total liabilities and stockholders' equity	$ 1,328,982	$ 1,367,163