Revenue (Disaggregation Of Revenues, By Type) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 166,928	$ 356,600	$ 356,585	$ 672,278	$ 1,089,297
Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	56,001		111,185	227,344	312,946
Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	21,559		75,973	103,957	273,727
Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	56,355		98,787	212,352	305,239
Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	33,013		70,640	128,625	197,385
Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	97,001		211,540	367,846	689,248
Services [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	11,130		18,835	38,719	52,997
Services [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	20,461		67,022	94,277	245,055
Services [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	44,550		85,188	167,081	262,658
Services [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	20,860		40,495	67,769	128,538
Rentals [Member]
Disaggregation of Revenue [Line Items]
Total revenues	42,562		99,771	196,006	282,819
Rentals [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	38,786		78,714	161,188	221,306
Rentals [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	1,098		8,951	9,680	28,672
Rentals [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	2,246		9,216	16,106	25,068
Rentals [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	432		2,890	9,032	7,773
Product Sales [Member]
Disaggregation of Revenue [Line Items]
Total revenues	27,365		45,274	108,426	117,230
Product Sales [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	6,085		13,636	27,437	38,643
Product Sales [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	9,559		4,383	29,165	17,513
Product Sales [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 11,721		$ 27,255	$ 51,824	$ 61,074