Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 436,315	$ 535,548	$ 903,491	$ 1,017,866
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	296,428	369,810	626,591	713,270
Depreciation, depletion, amortization and accretion	75,218	97,973	157,657	203,692
General and administrative expenses	71,984	69,896	145,829	145,716
Reduction in value of assets	31,381		31,381
Loss from operations	(38,696)	(2,131)	(57,967)	(44,812)
Interest income (expense), net	(24,650)	(24,894)	(49,771)	(49,781)
Other expense	490	(2,382)	(1,122)	(4,117)
Loss from continuing operations before income taxes	(62,856)	(29,407)	(108,860)	(98,710)
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Total revenues	100,682	94,033	201,761	179,235
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	37,864	36,599	80,069	71,669
Depreciation, depletion, amortization and accretion	21,490	28,590	44,516	58,231
General and administrative expenses	15,241	13,843	29,810	26,367
Loss from operations	26,087	15,001	47,366	22,968
Loss from continuing operations before income taxes	26,087	15,001	47,366	22,968
Onshore Completion and Workover Services [Member]
Segment Reporting Information [Line Items]
Total revenues	163,495	276,242	368,533	507,731
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	140,984	210,206	312,783	390,857
Depreciation, depletion, amortization and accretion	33,387	47,423	71,130	95,078
General and administrative expenses	9,005	11,102	19,580	24,328
Reduction in value of assets	31,381		31,381
Loss from operations	(51,262)	7,511	(66,341)	(2,532)
Loss from continuing operations before income taxes	(51,262)	7,511	(66,341)	(2,532)
Production Services [Member]
Segment Reporting Information [Line Items]
Total revenues	103,002	102,004	206,452	202,721
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	78,418	85,129	158,299	171,065
Depreciation, depletion, amortization and accretion	13,172	14,303	27,312	33,583
General and administrative expenses	7,970	9,696	15,782	19,289
Loss from operations	3,442	(7,124)	5,059	(21,216)
Loss from continuing operations before income taxes	3,442	(7,124)	5,059	(21,216)
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Total revenues	69,136	63,269	126,745	128,179
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	39,162	37,876	75,440	79,679
Depreciation, depletion, amortization and accretion	5,979	6,273	12,289	14,003
General and administrative expenses	15,522	13,323	31,459	27,383
Loss from operations	8,473	5,797	7,557	7,114
Interest income (expense), net	1,035	971	2,053	1,927
Loss from continuing operations before income taxes	9,508	6,768	9,610	9,041
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, amortization and accretion	1,190	1,384	2,410	2,797
General and administrative expenses	24,246	21,932	49,198	48,349
Loss from operations	(25,436)	(23,316)	(51,608)	(51,146)
Interest income (expense), net	(25,685)	(25,865)	(51,824)	(51,708)
Other expense	490	(2,382)	(1,122)	(4,117)
Loss from continuing operations before income taxes	$ (50,631)	$ (51,563)	$ (104,554)	$ (106,971)