Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 425,717	$ 573,068	$ 1,329,208	$ 1,590,934
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	294,206	404,389	920,797	1,117,659
Depreciation, depletion, amortization and accretion	67,389	99,892	225,046	303,584
General and administrative expenses	62,768	68,895	208,597	214,611
Reduction in value of assets	9,571		40,952
Loss from operations	(8,217)	(108)	(66,184)	(44,920)
Interest income (expense), net	(24,505)	(24,952)	(74,275)	(74,733)
Other income (expense)	(3,353)	(277)	(4,476)	(4,394)
Loss from continuing operations before income taxes	(36,075)	(25,337)	(144,935)	(124,047)
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Total revenues	111,185	99,184	312,946	278,419
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	38,663	37,328	118,732	108,997
Depreciation, depletion, amortization and accretion	20,168	27,830	64,684	86,061
General and administrative expenses	14,363	13,771	44,173	40,138
Loss from operations	37,991	20,255	85,357	43,223
Loss from continuing operations before income taxes	37,991	20,255	85,357	43,223
Onshore Completion and Workover Services [Member]
Segment Reporting Information [Line Items]
Total revenues	145,105	294,869	513,638	802,600
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	123,617	239,348	436,400	630,205
Depreciation, depletion, amortization and accretion	29,080	47,299	100,210	142,377
General and administrative expenses	10,046	5,455	29,626	29,783
Reduction in value of assets	566		31,947
Loss from operations	(18,204)	2,767	(84,545)	235
Loss from continuing operations before income taxes	(18,204)	2,767	(84,545)	235
Production Services [Member]
Segment Reporting Information [Line Items]
Total revenues	98,787	105,870	305,239	308,591
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	82,556	84,312	240,855	255,377
Depreciation, depletion, amortization and accretion	12,063	17,085	39,375	50,668
General and administrative expenses	2,905	10,471	18,687	29,760
Reduction in value of assets	1,997		1,997
Loss from operations	(734)	(5,998)	4,325	(27,214)
Loss from continuing operations before income taxes	(734)	(5,998)	4,325	(27,214)
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Total revenues	70,640	73,145	197,385	201,324
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	49,370	43,401	124,810	123,080
Depreciation, depletion, amortization and accretion	4,909	6,329	17,198	20,332
General and administrative expenses	14,935	14,453	46,394	41,836
Reduction in value of assets	7,008		7,008
Loss from operations	(5,582)	8,962	1,975	16,076
Interest income (expense), net	1,051	986	3,104	2,913
Loss from continuing operations before income taxes	(4,531)	9,948	5,079	18,989
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, amortization and accretion	1,169	1,349	3,579	4,146
General and administrative expenses	20,519	24,745	69,717	73,094
Loss from operations	(21,688)	(26,094)	(73,296)	(77,240)
Interest income (expense), net	(25,556)	(25,938)	(77,379)	(77,646)
Other income (expense)	(3,353)	(277)	(4,476)	(4,394)
Loss from continuing operations before income taxes	$ (50,597)	$ (52,309)	$ (155,151)	$ (159,280)