Segment Information (Schedule Of Identifiable Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Identifiable Assets	$ 1,340,587	$ 1,501,079
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	399,537	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	694,074	260,339
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 246,976	$ 132,021