Revenue (Disaggregation Of Revenues, By Type) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 535,548	$ 470,068	$ 1,017,866	$ 871,004
Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	94,033	68,827	179,235	137,258
Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	276,242	249,079	507,731	454,058
Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	102,004	88,606	202,721	157,211
Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	63,269	63,556	128,179	122,477
Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	446,812	404,131	846,580	738,581
Services [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	27,461	19,629	51,466	36,500
Services [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	266,071	240,461	487,418	439,907
Services [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	93,678	82,575	188,292	145,857
Services [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	59,602	61,466	119,404	116,317
Rentals [Member]
Disaggregation of Revenue [Line Items]
Total revenues	88,736	65,937	171,286	132,423
Rentals [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	66,572	49,198	127,769	100,758
Rentals [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	10,171	8,618	20,313	14,151
Rentals [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	8,326	6,031	14,429	11,354
Rentals [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 3,667	$ 2,090	$ 8,775	$ 6,160