Discontinued Operations (Components Of Income (Loss) From Discontinued Operations) (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, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
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
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)
Other expense	(2,105)	(6,224)	(1,399)			(6,499)	(4,810)
Loss from discontinued operations, net of income tax	(352)	(5,161)	(69,914)			$ (33,967)	(138,002)
Pumpco [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	10,719	16,985	30,996		$ 85,351		150,992
Cost of services	10,398	6,883	29,216		62,364		145,297
Depreciation, depletion, amortization and accretion	2,141	146	7,055		31,502		24,261
General and administrative expenses	1,119	2,379	4,101		8,597		21,576
Reduction in value of assets		14,475	60,230		26,905		109,591
Loss from operations	(2,939)	(6,898)	(69,606)		(44,017)		(149,733)
Other expense	2,485	238	6		188		21
Loss from discontinued operations before tax	(454)	(6,660)	(69,600)		(43,829)		(149,712)
Income tax expense (benefit)	102	1,499	(314)		9,862		11,710
Loss from discontinued operations, net of income tax	$ (352)	$ (5,161)	$ (69,914)		$ (33,967)		$ (138,002)