Revenue (Disaggregation Of Revenues, By Geography) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenues	$ 539,331	$ 573,068	$ 535,548	$ 482,318	$ 497,043	$ 506,029	$ 470,068	$ 400,936	$ 2,130,265	$ 1,874,076	$ 1,450,047
Drilling Products And Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									383,719	293,690	293,543
Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									418,525	372,781	348,363
Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues									270,365	272,422	284,176
U.S. Land [Member]
Disaggregation of Revenue [Line Items]
Total revenues									1,460,604	1,238,954	717,748
U.S. Land [Member] | Drilling Products And Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									176,448	117,856	64,251
U.S. Land [Member] | Onshore Completion and Workover Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									1,057,656	935,183	523,966
U.S. Land [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									195,363	151,632	87,434
U.S. Land [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues									31,137	34,283	42,097
Gulf Of Mexico [Member]
Disaggregation of Revenue [Line Items]
Total revenues									327,874	327,306	362,765
Gulf Of Mexico [Member] | Drilling Products And Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									100,855	91,507	120,323
Gulf Of Mexico [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									66,512	74,033	84,839
Gulf Of Mexico [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues									160,507	161,766	157,603
International [Member]
Disaggregation of Revenue [Line Items]
Total revenues									341,787	307,816	369,534
International [Member] | Drilling Products And Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									106,416	84,327	108,968
International [Member] | Production Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues									156,650	147,116	176,090
International [Member] | Technical Solutions [Member]
Disaggregation of Revenue [Line Items]
Total revenues									$ 78,721	$ 76,373	$ 84,476