Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended	8 Months Ended		9 Months Ended
	Feb. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 45,928	$ 178,583	$ 135,976		$ 450,318	$ 450,318	$ 521,797	$ 521,797
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)	29,773	124,973	87,074			296,420		318,013
Depreciation, depletion, amortization and accretion	8,358	59,208	28,163			158,256		89,052
General and administrative expenses	11,052	33,671	51,440			84,417		164,957
Restructuring and other expenses	1,270	4,712	25,746			20,533		27,033
Reduction in value of assets	0	0	2,929	$ 16,500		0		19,451
Loss from operations	(4,525)	(43,981)	(59,376)			(109,308)		(96,709)
Interest income (expense), net	202	647	(24,800)			1,394		(74,698)
Reorganization items, net	335,560					0		0
Other income (expense)	(2,105)	(6,224)	(1,399)			(6,499)		(4,810)
Income (loss) from continuing operations before income taxes	329,132	(49,558)	(85,575)			(114,413)		(176,217)
Rentals [Member]
Segment Reporting Information [Line Items]
Revenues	18,339	76,217				185,902
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)	7,839	33,438				76,793
Depreciation, depletion, amortization and accretion	4,271	41,641				111,781
General and administrative expenses	2,027	7,184				16,986
Loss from operations	4,202	(6,046)				(19,658)
Interest income (expense), net	10	(7)				(7)
Reorganization items, net	(2,037)
Other income (expense)	(399)	1,754				1,053
Income (loss) from continuing operations before income taxes	1,776	(4,299)				(18,612)
Well Services [Member]
Segment Reporting Information [Line Items]
Revenues	27,589	102,366				264,416
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)	21,934	91,535				219,627
Depreciation, depletion, amortization and accretion	3,666	15,615				41,991
General and administrative expenses	4,111	13,445				35,029
Loss from operations	(2,122)	(18,229)				(32,231)
Interest income (expense), net	1					3
Reorganization items, net	31,816
Other income (expense)	(165)	3,204				5,439
Income (loss) from continuing operations before income taxes	29,530	(15,025)				(26,789)
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Revenues			56,001					227,344
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)			23,714					81,163
Depreciation, depletion, amortization and accretion			14,424					48,042
General and administrative expenses			12,948					38,388
Loss from operations			4,915					59,751
Income (loss) from continuing operations before income taxes			4,915					59,751
Production Services [Member]
Segment Reporting Information [Line Items]
Revenues			46,962					165,828
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)			38,899					137,689
Depreciation, depletion, amortization and accretion			7,931					23,526
General and administrative expenses			6,594					20,281
Reduction in value of assets			0					4,096
Loss from operations			(6,462)					(19,764)
Income (loss) from continuing operations before income taxes			(6,462)					(19,764)
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Revenues			33,013					128,625
Cost of revenues (exclusive of depreciation, depletion, amortization and accretion)			24,461					99,161
Depreciation, depletion, amortization and accretion			4,983					14,663
General and administrative expenses			9,844					34,044
Reduction in value of assets			2,929					15,355
Loss from operations			(9,204)					(34,598)
Interest income (expense), net			(1,122)					3,399
Income (loss) from continuing operations before income taxes			(8,082)					(31,199)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, amortization and accretion	421	1,952	825			4,484		2,821
General and administrative expenses	4,914	13,042	22,054			32,402		72,244
Restructuring and other expenses	1,270	4,712	25,746			20,533		27,033
Loss from operations	(6,605)	(19,706)	(48,625)			(57,419)		(102,098)
Interest income (expense), net	191	654	(25,922)			1,398		(78,097)
Reorganization items, net	305,781
Other income (expense)	(1,541)	(11,182)	(1,399)			(12,991)		(4,810)
Income (loss) from continuing operations before income taxes	$ 297,826	$ (30,234)	$ (75,946)			$ (69,012)		$ (185,005)