Business Segments - Capital Expenditures (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Capital expenditures	$ 118,341	$ 122,921
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	1,331	526
Operating Segments | Contract Drilling
Segment Reporting Information [Line Items]
Capital expenditures	75,725	75,247
Operating Segments | Pressure Pumping
Segment Reporting Information [Line Items]
Capital expenditures	31,400	24,923
Operating Segments | Directional Drilling
Segment Reporting Information [Line Items]
Capital expenditures	2,112	12,829
Other Operations
Segment Reporting Information [Line Items]
Capital expenditures	$ 7,773	$ 9,396