Business Segments - Income (Loss) Before Income Taxes (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	$ (109,410,000)	$ (159,084,000)	$ (226,937,000)	$ (653,494,000)
Credit loss expense	0	(4,551,000)	0	(5,606,000)
Interest income	20,000	334,000	159,000	991,000
Interest expense	(10,704,000)	(10,984,000)	(20,713,000)	(22,208,000)
Other	812,000	85,000	826,000	170,000
Loss before income taxes	(119,282,000)	(169,649,000)	(246,665,000)	(674,541,000)
Corporate
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(18,863,000)	(30,497,000)	(38,551,000)	(54,982,000)
Operating Segments | Contract Drilling
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(58,229,000)	(30,742,000)	(106,850,000)	(434,760,000)
Operating Segments | Pressure Pumping
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(23,921,000)	(68,554,000)	(63,660,000)	(104,040,000)
Operating Segments | Directional Drilling
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	(5,110,000)	(14,385,000)	(10,033,000)	(24,980,000)
Other Operations
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)	$ (3,287,000)	$ (10,355,000)	$ (7,843,000)	$ (29,126,000)