Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Current Assets:
Cash and cash equivalents	$ 35,219	$ 50,038	$ 60,684
Accounts receivable, net	582,532	457,910	566,425
Inventories, net	576,429	521,624	508,199
Other current assets	83,809	56,813	56,217
Total Current Assets	1,277,989	1,086,385	1,191,525
Property, plant and equipment	6,375,813	6,115,530	6,013,084
Allowances for depreciation, depletion and amortization	(2,854,236)	(2,692,135)	(2,633,471)
Net property, plant and equipment	3,521,577	3,423,395	3,379,613
Goodwill	2,160,060	2,159,337	2,160,605
Operating permits, net	440,846	442,202	444,123
Other intangibles, net	63,740	69,110	70,927
Other noncurrent assets	102,573	120,476	126,408
Total Assets	7,566,785	7,300,905	7,373,201
Current Liabilities:
Bank overdraft	1,047
Accounts payable	163,597	178,598	192,738
Accrued salaries, benefits and payroll taxes	37,885	47,428	33,463
Pension and postretirement benefits	12,073	9,293	9,658
Accrued insurance and other taxes	70,323	60,093	67,822
Current maturities of long-term debt and short-term facilities	80,038	180,036	228,025
Accrued interest	28,082	16,837	23,060
Other current liabilities	75,458	54,303	50,143
Total Current Liabilities	468,503	546,588	604,909
Long-term debt	1,642,502	1,506,153	1,536,810
Pension, postretirement and postemployment benefits	230,212	248,086	200,152
Deferred income taxes, net	662,982	663,019	676,144
Other noncurrent liabilities	228,604	194,469	196,788
Total Liabilities	3,232,803	3,158,315	3,214,803
Equity:
Common stock, par value $0.01 per share	627	630	633
Preferred stock, par value $0.01 per share
Additional paid-in capital	3,362,744	3,334,461	3,326,531
Accumulated other comprehensive loss	(122,928)	(130,687)	(104,511)
Retained earnings	1,090,778	935,574	932,679
Total Shareholders' Equity	4,331,221	4,139,978	4,155,332
Noncontrolling interests	2,761	2,612	3,066
Total Equity	4,333,982	4,142,590	4,158,398
Total Liabilities and Equity	$ 7,566,785	$ 7,300,905	$ 7,373,201