Business Segments - Revenues (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues		$ 220,801	$ 207,141	$ 250,380	$ 445,927	$ 492,297	$ 598,452	$ 675,765	$ 704,171	$ 1,124,249	$ 2,470,685	$ 3,326,997
Contract Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										669,126	1,308,350	1,430,492
Pressure Pumping
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										336,111	868,694	1,573,396
Directional Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										73,356	188,786	209,275
Operating Segments | Contract Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										670,357	1,309,988	1,432,012
Operating Segments | Pressure Pumping
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										336,111	868,694	1,573,396
Operating Segments | Directional Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues										73,356	188,786	209,275
Other Operations
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues	[1]									57,962	122,885	131,028
Intersegment Elimination | Contract Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues	[2]									(1,231)	(1,638)	(1,520)
Intersegment Elimination | Other Operations
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues	[2]									$ (12,306)	$ (18,030)	$ (17,194)

[1] Other operations includes our oilfield rentals business, drilling equipment service business, the electrical controls and automation business and the oil and natural gas working interests.

[2] Intercompany revenues consist of revenues from contract drilling for services provided to our other operations, and revenues from other operations for services provided to contract drilling, pressure pumping and within other operations. These revenues are generally based on estimated external selling prices and are eliminated during consolidation.