Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 354,418	$ 326,225	$ 356,271	$ 413,133	$ 545,150	$ 601,396	$ 710,784	$ 917,235	$ 1,450,047	$ 2,774,565	$ 4,556,622
Cost of goods and services	321,132	258,168	258,635	285,339	397,548	420,485	465,533	582,246	1,123,274	1,865,812	2,734,833
Depreciation, depletion, amortization and accretion - services	117,954	123,308	132,037	136,672	144,818	146,757	158,352	$ 162,220	509,971	612,147	650,814
General and administrative expenses									346,606	510,708	624,371
Reduction in the value of assets	$ 35,961	$ 1,963	$ 460,283	$ 2,198	$ 175,618	$ 755,632	$ 807,637		500,405	1,738,887
Income from operations									(1,030,209)	(1,952,989)	546,604
Interest expense, net									92,753	97,318	96,734
Other income (expense)									22,621	(9,476)	(7,681)
Income (loss) from continuing operations before income taxes									(1,100,341)	(2,059,783)	442,189
Drilling Products And Services [Member]
Segment Reporting Information [Line Items]
Revenues									293,543	547,530	852,499
Cost of goods and services									136,719	178,629	255,613
Depreciation, depletion, amortization and accretion - services									161,378	187,336	179,934
General and administrative expenses									89,574	120,637	141,762
Reduction in the value of assets									48,903	40,237
Income from operations									(143,031)	20,691	275,190
Income (loss) from continuing operations before income taxes									(143,031)	20,691	275,190
Onshore Completion Services [Member]
Segment Reporting Information [Line Items]
Revenues									523,965	934,274	1,732,833
Cost of goods and services									515,784	773,119	1,205,443
Depreciation, depletion, amortization and accretion - services									209,455	225,667	233,430
General and administrative expenses									91,508	121,289	159,687
Reduction in the value of assets									190,835	783,229
Income from operations									(483,617)	(969,030)	134,273
Income (loss) from continuing operations before income taxes									(483,617)	(969,030)	134,273
Production Services [Member]
Segment Reporting Information [Line Items]
Revenues									348,363	795,215	1,402,815
Cost of goods and services									276,223	612,578	967,440
Depreciation, depletion, amortization and accretion - services									95,416	136,992	171,380
General and administrative expenses									76,817	146,192	195,731
Reduction in the value of assets									235,067	790,517
Income from operations									(335,160)	(891,064)	68,264
Interest expense, net									1,343	2,013
Income (loss) from continuing operations before income taxes									(336,503)	(893,077)	68,264
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Revenues									284,176	497,546	568,475
Cost of goods and services									194,548	301,486	306,337
Depreciation, depletion, amortization and accretion - services									43,722	62,152	66,070
General and administrative expenses									88,707	122,590	127,191
Reduction in the value of assets									25,600	124,904
Income from operations									(68,401)	(113,586)	68,877
Interest expense, net									(3,553)	(1,707)	(1,577)
Income (loss) from continuing operations before income taxes									(64,848)	(111,879)	70,454
Unallocated [Member]
Segment Reporting Information [Line Items]
Interest expense, net									94,963	97,012	98,311
Other income (expense)									22,621	(9,476)	(7,681)
Income (loss) from continuing operations before income taxes									$ (72,342)	$ (106,488)	$ (105,992)