Business Segments - Assets (Detail) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Asset Reconciling Item [Line Items]
Total assets		$ 5,819,942	$ 5,758,856
Other Operations
Segment Reporting Asset Reconciling Item [Line Items]
Total assets		174,141	172,094
Corporate
Segment Reporting Asset Reconciling Item [Line Items]
Total assets	[1]	299,218	144,069
Operating Segments | Contract Drilling
Segment Reporting Asset Reconciling Item [Line Items]
Total assets		3,844,276	3,931,994
Operating Segments | Pressure Pumping
Segment Reporting Asset Reconciling Item [Line Items]
Total assets		1,178,927	1,209,424
Operating Segments | Directional Drilling
Segment Reporting Asset Reconciling Item [Line Items]
Total assets		$ 323,380	$ 301,275

[1] Corporate assets primarily include cash on hand and certain property and equipment.