Business Segments - Income (Loss) Before Income Taxes (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	$ (117,527,000)	$ (494,410,000)
Credit loss expense	0	(1,055,000)
Interest income	139,000	657,000
Interest expense	(10,009,000)	(11,224,000)
Other	14,000	85,000
Loss before income taxes	(127,383,000)	(504,892,000)
Corporate
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(19,688,000)	(24,485,000)
Operating Segments | Contract Drilling
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(48,621,000)	(404,018,000)
Operating Segments | Pressure Pumping
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(39,739,000)	(35,486,000)
Operating Segments | Directional Drilling
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(4,923,000)	(10,595,000)
Other Operations
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	$ (4,556,000)	$ (18,771,000)