Interim Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]
Revenues	$ 545,150	$ 601,396	$ 710,784	$ 917,235	$ 1,178,626	$ 1,209,026	$ 1,107,552	$ 1,061,418	$ 2,774,565	$ 4,556,622	$ 4,350,057
Costs and Expenses [Abstract]
Cost of services and rentals	397,548	420,485	465,533	582,246	711,243	721,692	650,293	651,605	1,865,812	2,734,833	2,633,590
Depreciation, depletion, amortization and accretion	144,818	146,757	158,352	162,220	157,377	170,154	160,965	162,318	612,147	650,814	604,441
Gross Profit	2,784	34,154	86,899	172,769	310,006	317,180	296,294	247,495
Reduction in value of assets	175,618	755,632	807,637						1,738,887		300,078
Net income (loss) from continuing operations	(214,547)	(816,587)	(775,132)	(1,497)	73,364	85,743	79,057	42,626	(1,807,763)	280,790	45,485
Loss from discontinued operations, net of tax	(22,848)	(4,610)	(9,857)	(9,640)	(7,238)	(5,886)	(3,895)	(5,954)	(46,955)	(22,973)	(156,903)
Net Income (Loss)	$ (237,395)	$ (821,197)	$ (784,989)	$ (11,137)	$ 66,126	$ 79,857	$ 75,162	$ 36,672	$ (1,854,718)	$ 257,817	$ (111,418)
Earnings Per Share [Abstract]
Continuing operations, basic	$ (1.43)	$ (5.42)	$ (5.15)	$ (0.02)	$ 0.49	$ 0.55	$ 0.51	$ 0.27	$ (12.02)	$ 1.81	$ 0.29
Continuing operations, diluted					0.48	0.55	0.50	0.27	(12.02)	1.79	0.28
Discontinued operations, basic	$ (0.15)	$ (0.03)	$ (0.07)	$ (0.06)	$ (0.05)	$ (0.03)	$ (0.03)	$ (0.04)	(0.31)	(0.15)	(0.99)
Discontinued operations, diluted									$ (0.31)	$ (0.14)	$ (0.97)