Discontinued Operations (Assets And Liabilities Of Discontinued Operation) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total current assets	$ 41,881	$ 47,635
Total assets	51,000
Total liabilities	1,177	4,079
Pumpco [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other current assets	1,997	2,155
Total current assets	1,997	2,155
Property, plant and equipment, net	39,863	45,397
Operating lease ROU assets	21	83
Total assets	41,881	47,635
Accounts payable		165
Accrued expenses	1,177	1,326
Total current liabilities	1,177	1,491
Operating lease liabilities		2,588
Total liabilities	$ 1,177	$ 4,079