Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Current Assets:
Cash and cash equivalents	$ 36,722	$ 50,038	$ 28,596
Accounts receivable, net	570,618	457,910	534,459
Inventories, net	549,865	521,624	504,877
Other current assets	87,092	56,813	53,997
Total Current Assets	1,244,297	1,086,385	1,121,929
Property, plant and equipment	6,306,083	6,115,530	5,896,512
Allowances for depreciation, depletion and amortization	(2,800,823)	(2,692,135)	(2,574,307)
Net property, plant and equipment	3,505,260	3,423,395	3,322,205
Goodwill	2,160,060	2,159,337	2,136,783
Operating permits, net	437,713	442,202	442,349
Other intangibles, net	65,526	69,110	64,327
Other noncurrent assets	103,004	120,476	145,712
Total Assets	7,515,860	7,300,905	7,233,305
Current Liabilities:
Bank overdraft	3,794		7,143
Accounts payable	187,227	178,598	197,733
Accrued salaries, benefits and payroll taxes	36,202	47,428	24,864
Pension and postretirement benefits	8,802	9,293	9,120
Accrued insurance and other taxes	59,958	60,093	62,525
Current maturities of long-term debt and short-term facilities	140,037	180,036	238,155
Other current liabilities	98,305	71,140	62,064
Total Current Liabilities	534,325	546,588	601,604
Long-term debt	1,641,944	1,506,153	1,541,062
Pension, postretirement and postemployment benefits	253,908	248,086	236,562
Deferred income taxes, net	663,414	663,019	639,776
Other noncurrent liabilities	221,738	194,469	197,801
Total Liabilities	3,315,329	3,158,315	3,216,805
Equity:
Common stock, par value $0.01 per share	627	630	633
Preferred stock, par value $0.01 per share
Additional paid-in capital	3,355,992	3,334,461	3,318,859
Accumulated other comprehensive loss	(125,906)	(130,687)	(106,068)
Retained earnings	967,058	935,574	800,028
Total Shareholders' Equity	4,197,771	4,139,978	4,013,452
Noncontrolling interests	2,760	2,612	3,048
Total Equity	4,200,531	4,142,590	4,016,500
Total Liabilities and Equity	$ 7,515,860	$ 7,300,905	$ 7,233,305