Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 321,497	$ 365,274
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion	211,686	240,053
Depreciation, depletion, amortization and accretion	41,355	56,343
General and administrative expenses	65,157	71,112
Reduction in value of assets	16,522
Loss from operations	(13,223)	(2,234)
Interest income (expense), net	(25,134)	(25,121)
Other expense	(4,232)	(1,612)
Loss from continuing operations before income taxes	(42,589)	(28,967)
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Total revenues	103,993	101,079
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion	34,963	42,205
Depreciation, depletion, amortization and accretion	17,790	23,026
General and administrative expenses	14,513	14,569
Loss from operations	36,727	21,279
Loss from continuing operations before income taxes	36,727	21,279
Onshore Completion and Workover Services [Member]
Segment Reporting Information [Line Items]
Total revenues	61,218	103,136
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion	52,589	81,689
Depreciation, depletion, amortization and accretion	6,313	11,647
General and administrative expenses	5,314	7,842
Loss from operations	(2,998)	1,958
Loss from continuing operations before income taxes	(2,998)	1,958
Production Services [Member]
Segment Reporting Information [Line Items]
Total revenues	101,504	103,450
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion	82,612	79,881
Depreciation, depletion, amortization and accretion	10,838	14,140
General and administrative expenses	7,855	7,812
Reduction in value of assets	4,096
Loss from operations	(3,897)	1,617
Loss from continuing operations before income taxes	(3,897)	1,617
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Total revenues	54,782	57,609
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion	41,522	36,278
Depreciation, depletion, amortization and accretion	5,345	6,310
General and administrative expenses	13,991	15,937
Reduction in value of assets	12,426
Loss from operations	(18,502)	(916)
Interest income (expense), net	1,173	1,018
Loss from continuing operations before income taxes	(17,329)	102
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, amortization and accretion	1,069	1,220
General and administrative expenses	23,484	24,952
Loss from operations	(24,553)	(26,172)
Interest income (expense), net	(26,307)	(26,139)
Other expense	(4,232)	(1,612)
Loss from continuing operations before income taxes	$ (55,092)	$ (53,923)