Segment Information (Schedule Of Identifiable Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Identifiable Assets	$ 1,224,359	$ 1,199,508
Rentals [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	421,865	379,453
Well Services [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	628,863	636,256
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 173,631	$ 183,799