Chapter 11 Proceedings - Debtor-in-Possession Condensed Combined Statement of Operations (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Total revenues	$ 198,203		$ 216,706	$ 427,373	$ 450,248
Operating expenses:
Depreciation	74,835		88,253	167,878	175,151
General and administrative	15,701		15,294	32,046	32,605
Impairment of assets		$ 774,000		774,028
Restructuring and separation costs	17,119			17,119
Gain on disposition of assets	(220)		(9,436)	(3,653)	(5,149)
Total operating expenses	281,685		328,206	1,357,292	610,874
Operating loss	(83,482)		(111,500)	(929,919)	(160,626)
Other income (expense):
Interest income	108		1,933	498	4,346
Interest expense, net of amounts capitalized	(10,333)		(31,159)	(42,655)	(61,084)
Foreign currency transaction gain	(1,004)		(721)	(797)	(1,806)
Reorganization items, net	(53,977)			(53,977)
Other, net	(81)		105	242	438
Loss before income tax benefit	(148,769)		(141,342)	(1,026,608)	(218,732)
Income tax benefit	3,949		27,354	19,848	31,416
Net loss	$ (144,820)		$ (113,988)	$ (1,006,760)	$ (187,316)
Weighted-average shares outstanding:
Shares of common stock	138,043		137,691	137,937	137,607
Total weighted-average shares outstanding	138,043		137,691	137,937	137,607
Contract Drilling [Member]
Revenues:
Total revenues	$ 188,637		$ 207,273	$ 406,503	$ 433,970
Operating expenses:
Contract drilling, excluding depreciation	165,943		224,782	350,455	392,210
Reimbursable Expenses [Member]
Revenues:
Total revenues	9,566		9,433	20,870	16,278
Operating expenses:
Contract drilling, excluding depreciation	$ 8,307		$ 9,313	19,419	$ 16,057
Debtor [Member]
Revenues:
Total revenues				370,613
Operating expenses:
Depreciation				167,392
General and administrative				29,405
Impairment of assets				774,028
Restructuring and separation costs				15,085
Gain on disposition of assets				(3,615)
Total operating expenses				1,302,813
Operating loss				(932,200)
Other income (expense):
Interest income				488
Interest expense, net of amounts capitalized				(49,631)
Foreign currency transaction gain				1,194
Reorganization items, net				(53,977)
Other, net				(456)
Loss before income tax benefit				(1,034,582)
Income tax benefit				25,864
Net loss				(1,008,718)
Debtor [Member] | Contract Drilling [Member]
Revenues:
Total revenues				349,704
Operating expenses:
Contract drilling, excluding depreciation				301,060
Debtor [Member] | Reimbursable Expenses [Member]
Revenues:
Total revenues				20,909
Operating expenses:
Contract drilling, excluding depreciation				$ 19,458