Revenue (Disaggregation Of Revenues, By Geography) (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
U.S. Land [Member]
Disaggregation of Revenue [Line Items]
Total revenues	375,438	317,832	706,934	576,493
U.S. Land [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	43,394	27,770	84,111	48,932
U.S. Land [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	276,242	249,079	507,731	454,058
U.S. Land [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	47,944	33,062	100,401	56,497
U.S. Land [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	7,858	7,921	14,691	17,006
Gulf Of Mexico [Member]
Disaggregation of Revenue [Line Items]
Total revenues	72,228	84,233	148,279	159,181
Gulf Of Mexico [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	23,261	22,266	44,250	45,751
Gulf Of Mexico [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	13,634	19,937	31,134	37,683
Gulf Of Mexico [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	35,333	42,030	72,895	75,747
International [Member]
Disaggregation of Revenue [Line Items]
Total revenues	87,882	68,003	162,653	135,330
International [Member] | Drilling Products and Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	27,378	18,791	50,874	42,575
International [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	40,426	35,607	71,186	63,031
International [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 20,078	$ 13,605	$ 40,593	$ 29,724