Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Current Assets:
Cash and cash equivalents	$ 27,242	$ 168,409	$ 56,366
Accounts receivable, net	448,048	410,921	381,389
Inventories, net	485,367	469,141	505,047
Other current assets	37,658	33,164	103,027
Total Current Assets	998,315	1,081,635	1,045,829
Property, plant and equipment	5,778,368	5,613,198	5,694,546
Allowances for depreciation, depletion and amortization	(2,515,387)	(2,457,198)	(2,329,440)
Net property, plant and equipment	3,262,981	3,156,000	3,365,106
Goodwill	2,135,295	2,068,235	2,071,471
Other noncurrent assets	142,281	141,189	102,959
Total Assets	7,058,287	6,957,611	7,177,319
Current Liabilities:
Bank overdraft		10,235
Accounts payable	174,398	164,718	184,066
Accrued salaries, benefits and payroll taxes	17,052	30,939	23,590
Pension and postretirement benefits	9,169	8,168	6,637
Accrued insurance and other taxes	52,501	62,781	58,742
Current maturities of long-term debt and short-term facilities	177,430	18,713	13,873
Accrued interest	23,004	16,156	22,461
Other current liabilities	38,577	54,948	33,653
Total Current Liabilities	492,131	366,658	343,022
Long-term debt	1,575,327	1,550,061	1,562,190
Pension, postretirement and postemployment benefits	226,924	224,538	252,923
Deferred income taxes, net	620,569	583,459	518,360
Other noncurrent liabilities	197,700	172,718	158,641
Total Liabilities	3,112,651	2,897,434	2,835,136
Equity:
Common stock, par value $0.01 per share	$ 633	$ 643	$ 673
Preferred stock, par value $0.01 per share
Additional paid-in capital	$ 3,302,258	$ 3,287,827	$ 3,255,809
Accumulated other comprehensive loss	(103,833)	(105,622)	(106,723)
Retained earnings	743,593	874,436	1,190,807
Total Shareholders' Equity	3,942,651	4,057,284	4,340,566
Noncontrolling interests	2,985	2,893	1,617
Total Equity	3,945,636	4,060,177	4,342,183
Total Liabilities and Equity	7,058,287	6,957,611	7,177,319
Operating Permits
Current Assets:
Intangibles, net	444,148	444,725	497,841
Other Intangible Assets
Current Assets:
Intangibles, net	$ 75,267	$ 65,827	$ 94,113

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.