CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 136,892	$ 131,835
Accounts receivable, net of allowance for doubtful accounts of $3,952 in 2017 and $2,553 in 2016	375,418	169,166
Inventories	113,359	108,316
Income taxes receivable	3,141	57,174
Prepaid expenses	5,587	6,718
Other current assets	8,043	5,848
Total current assets	642,440	479,057
Property, plant and equipment, less accumulated depreciation of $1,643,347 in 2017 and $1,595,508 in 2016	444,662	497,986
Goodwill	32,150	32,150
Other assets	29,374	26,259
Total assets	1,148,626	1,035,452
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	121,880	70,536
Accrued payroll and related expenses	25,254	12,130
Accrued insurance expenses	4,224	4,099
Accrued state, local and other taxes	7,706	3,094
Income taxes payable	4,201	4,929
Other accrued expenses	1,098	6,680
Total current liabilities	164,363	101,468
Long-term accrued insurance expenses	10,320	9,537
Long-term pension liabilities	34,934	32,864
Deferred income taxes	53,529	81,466
Other long-term liabilities	3,627	3,318
Total liabilities	266,773	228,653
Common stock	21,658	21,749
Capital in excess of par value	0	0
Retained earnings	877,320	803,152
Accumulated other comprehensive loss	(17,125)	(18,102)
Total stockholders' equity	881,853	806,799
Total liabilities and stockholders' equity	$ 1,148,626	$ 1,035,452