Business Segments - Income (Loss) from Continuing Operations Before Income Taxes (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)		$ (140,236)	$ (124,332)	$ (232,875)	$ (219,591)
Other operating income, net	[1]	1,806	4,822	14,710	6,167
Interest income		642	100	1,048	210
Interest expense		(9,075)	(10,678)	(17,345)	(21,478)
Other		131	17	148	33
Loss before income taxes		(148,538)	(134,893)	(249,024)	(240,826)
Other Operations
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)		(4,563)	740	(6,514)	(2,491)
Corporate
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)		(68,753)	(13,420)	(87,748)	(27,738)
Operating Segments | Contract Drilling
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)		(73,362)	(70,449)	(135,068)	(105,545)
Operating Segments | Pressure Pumping
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Operating income (loss)		$ 4,636	$ (46,025)	$ (18,255)	$ (89,984)

[1] Other operating income includes net gains associated with the disposal of assets related to corporate strategy decisions of the executive management group. Accordingly, the related gains have been excluded from the operating results of specific segments. This caption also includes expenses related to certain legal settlements net of insurance reimbursements.