Discontinued Operations (Schedule Of Cash Flows From Discontinued Operations) (Details) - Pumpco [Member] - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
Feb. 02, 2021	Mar. 31, 2021	Mar. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction in value of assets			$ 46,358
Proceeds from sales of assets	$ 486	$ 5,024	$ 8,449

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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