Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 414,829	$ 393,046
Accounts receivable, net of allowance for doubtful accounts of $22,834 and $22,076 at March 31, 2015 and December 31, 2014, respectively	770,846	926,768
Deferred Tax Assets, Net, Current	25,064	32,138
Prepaid expenses	69,772	74,750
Inventory and other current assets	203,412	185,429
Assets Held-for-sale, Current	144,905	116,680
Total current assets	1,628,828	1,728,811
Property, plant and equipment, net of accumulated depreciation and depletion of $2,394,123 and $2,269,542 at March 31, 2015 and December 31, 2014, respectively	2,690,491	2,733,839
Goodwill	2,465,646	2,468,409
Notes receivable	26,387	25,970
Intangible and other long-term assets, net of accumulated amortization of $87,177 and $81,386 at March 31, 2015 and December 31, 2014, respectively	411,806	420,360
Total assets	7,223,158	7,377,389
Current liabilities:
Accounts payable	212,609	225,306
Accrued expenses	337,273	363,747
Income taxes payable	8,723	40,213
Current maturities of long-term debt	21,533	20,941
Total current liabilities	598,137	712,047
Liabilities of Assets Held-for-sale	17,999	61,840
Deferred income taxes	693,123	702,996
Decommissioning liabilities	91,485	88,000
Long-term debt, net	1,622,713	1,627,842
Other long-term liabilities	163,396	166,766
Stockholders' equity:
Preferred stock of $0.01 par value. Authorized, 5,000,000 shares; none issued
Common stock of $0.001 par value. Authorized - 250,000,000, Issued and Outstanding - 150,363,047 as of March 31, 2015 Authorized - 250,000,000, Issued - 149,648,826, Outstanding, 149,708,825 at December 31, 2014	150	150
Additional Paid in Capital	2,632,926	2,620,328
Accumulated other comprehensive loss, net	(50,959)	(36,280)
Retained earnings	1,472,187	1,495,540
Total stockholders' equity	4,054,304	4,079,738
Total liabilities and stockholders' equity	$ 7,223,158	$ 7,377,389