Discontinued Operations (Components Of Income (Loss) From Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss from discontinued operations, net of income tax	$ (92,362)	$ (17,936)	$ (52,609)	$ (15,061)	$ (433,171)	$ 1,620	$ 7,427	$ (6,588)	$ (177,968)	$ (430,712)	$ (25,606)
Pumpco [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues									281,452	651,408	568,547
Cost of services									272,248	531,616	508,886
Income (loss) from discontinued operations before income tax									(169,582)	(433,142)	(84,813)
Loss from discontinued operations, net of income tax									$ (177,968)	$ (430,712)	$ (25,606)