Condensed Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Consolidated Statements of Operations [Abstract]
Services	$ 2,104,942	$ 3,466,279	$ 3,371,847
Rentals	669,623	1,090,343	978,210
Total, Revenues	2,774,565	4,556,622	4,350,057
Costs and expenses:
Cost of Services (exclusive of items shown separately below)	1,575,653	2,308,270	2,244,881
Cost of Rentals (exclusive of items shown separately below)	290,159	426,563	388,709
Cost of goods and services	1,865,812	2,734,833	2,633,590
Depreciation, depletion, amortization and accretion	612,147	650,814	604,441
General and administrative expenses	510,708	624,371	597,778
Reduction in value of assets	1,738,887		300,078
Income from operations	(1,952,989)	546,604	214,170
Other income (expense):
Interest expense, net	97,318	96,734	107,902
Other Expense	(9,476)	(7,681)	(5,511)
Income from continuing operations before income taxes	(2,059,783)	442,189	100,757
Income taxes	(252,020)	161,399	55,272
Net income from continuing operations	(1,807,763)	280,790	45,485
Loss from discontinued operations, net of tax	(46,955)	(22,973)	(156,903)
Net income (loss)	$ (1,854,718)	$ 257,817	$ (111,418)
Earnings per share information:
Continuing operations, basic	$ (12.02)	$ 1.81	$ 0.29
Discontinued operations, basic	(0.31)	(0.15)	(0.99)
Basic earnings (loss) per share	(12.33)	1.66	(0.70)
Continuing operations, diluted	(12.02)	1.79	0.28
Discontinued operations, diluted	(0.31)	(0.14)	(0.97)
Diluted earnings per share	(12.33)	1.65	(0.69)
Cash dividends declared per share	$ 0.32	$ 0.24	$ 0.08
Weighted average common shares used in computing earnings per share:
Basic	150,461	155,154	159,206
Incremental common shares from stock based compensation		1,572	1,574
Diluted	150,461	156,726	160,780