Segment Information (Schedule Of Identifiable Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Identifiable Assets	$ 1,423,840	$ 1,501,079
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	970,767	557,469
Onshore Completion and Workover Services [Member]
Segment Reporting Information [Line Items]
Identifiable Assets		183,065
Production Services [Member]
Segment Reporting Information [Line Items]
Identifiable Assets		368,185
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	308,373	260,339
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 144,700	$ 132,021