Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ 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
Segment Reporting Information [Line Items]
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
Cost of goods and services	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
General and administrative expenses									510,708	624,371	597,778
Reduction in the value of assets	175,618	$ 755,632	$ 807,637						1,738,887		300,078
Income from operations									(1,952,989)	546,604	214,170
Interest expense, net									97,318	96,734	107,902
Other Expense									(9,476)	(7,681)	(5,511)
Income (loss) from continuing operations before income taxes									(2,059,783)	442,189	100,757
Identifiable Assets	4,914,244				7,317,782				4,914,244	7,317,782	7,366,943
Capital Expenditures									358,226	616,102	608,960
Drilling Products And Services [Member]
Segment Reporting Information [Line Items]
Revenues									583,139	904,358	820,538
Cost of goods and services									196,921	282,023	268,127
Depreciation, depletion, amortization and accretion									194,061	186,642	168,391
General and administrative expenses									127,525	149,967	136,244
Reduction in the value of assets									40,237		2,292
Income from operations									24,395	285,726	245,484
Income (loss) from continuing operations before income taxes									24,395	285,726	245,484
Identifiable Assets	1,223,191				1,284,842				1,223,191	1,284,842	1,237,842
Capital Expenditures									129,504	274,752	246,479
Onshore Completion Services [Member]
Segment Reporting Information [Line Items]
Revenues									934,274	1,732,833	1,607,268
Cost of goods and services									773,119	1,205,443	1,091,956
Depreciation, depletion, amortization and accretion									225,667	233,430	216,152
General and administrative expenses									121,289	159,687	158,448
Reduction in the value of assets									783,229		16,975
Income from operations									(969,030)	134,273	123,737
Income (loss) from continuing operations before income taxes									(969,030)	134,273	123,737
Identifiable Assets	1,929,185				2,993,824				1,929,185	2,993,824	2,961,390
Capital Expenditures									103,001	152,742	101,854
Production Services [Member]
Segment Reporting Information [Line Items]
Revenues									759,606	1,350,956	1,434,990
Cost of goods and services									594,286	941,030	1,002,628
Depreciation, depletion, amortization and accretion									130,267	164,672	177,532
General and administrative expenses									139,304	187,526	190,647
Reduction in the value of assets									790,517		28,568
Income from operations									(894,768)	57,728	35,615
Interest expense, net									2,013
Income (loss) from continuing operations before income taxes									(896,781)	57,728	35,615
Identifiable Assets	967,719				2,098,592				967,719	2,098,592	2,158,653
Capital Expenditures									72,048	88,870	122,946
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Revenues									497,546	568,475	487,261
Cost of goods and services									301,486	306,337	270,879
Depreciation, depletion, amortization and accretion									62,152	66,070	42,366
General and administrative expenses									122,590	127,191	112,439
Reduction in the value of assets									124,904		252,243
Income from operations									(113,586)	68,877	(190,666)
Interest expense, net									(1,707)	(1,577)	(1,323)
Other Expense											836
Income (loss) from continuing operations before income taxes									(111,879)	70,454	(188,507)
Identifiable Assets	$ 794,149				$ 940,524				794,149	940,524	1,009,058
Capital Expenditures									53,673	99,738	137,681
Unallocated [Member]
Segment Reporting Information [Line Items]
Interest expense, net									97,012	98,311	109,225
Other Expense									(9,476)	(7,681)	(6,347)
Income (loss) from continuing operations before income taxes									$ (106,488)	$ (105,992)	$ (115,572)