Segment Information (Schedule Of Capital Expenditures, By Segment) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Capital Expenditures		$ 47,653	$ 103,722	$ 113,276
Drilling Products And Services [Member]
Segment Reporting Information [Line Items]
Capital Expenditures		24,053	63,252	46,649
Onshore Completion And Workover Services [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	[1]	1,825	5,830	39,699
Pumpco capital expenditures			36,700	108,100
Production Services [Member]
Segment Reporting Information [Line Items]
Capital Expenditures		15,558	17,009	8,651
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Capital Expenditures		4,051	11,377	16,221
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Capital Expenditures		$ 2,166	$ 6,254	$ 2,056

[1] Excludes capital expenditures related to Pumpco of $36.7 million and $108.1 million for the years ended December 31, 2019, and 2018, respectively.