Chapter 11 Proceedings - Debtor-in-Possession Condensed Combined Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Total revenues	$ 134,817	$ 229,170
Operating expenses:
Depreciation	74,626	93,043
General and administrative	12,366	16,345
Impairment of assets	197,027	774,028
Gain on disposition of assets	(5,401)	(3,433)
Total operating expenses	432,028	1,075,607
Operating loss	(297,211)	(846,437)
Other income (expense):
Interest income	30	389
Interest expense, net of amounts capitalized	(32,562)	(32,321)
Foreign currency transaction gain	625	207
Reorganization items, net	(35,252)
Other, net	489	323
Loss before income tax benefit	(363,881)	(877,839)
Income tax benefit	2,200	15,899
Net loss	(361,681)	(861,940)
Contract Drilling [Member]
Revenues:
Total revenues	122,553	217,866
Operating expenses:
Contract drilling, excluding depreciation	141,573	184,511
Reimbursable Expenses [Member]
Revenues:
Total revenues	12,264	11,304
Operating expenses:
Contract drilling, excluding depreciation	11,837	$ 11,113
Debtor [Member]
Revenues:
Total revenues	131,397
Operating expenses:
Depreciation	74,496
General and administrative	12,039
Impairment of assets	197,027
Gain on disposition of assets	(3,442)
Total operating expenses	422,225
Operating loss	(290,828)
Other income (expense):
Interest income	15
Interest expense, net of amounts capitalized	(32,900)
Foreign currency transaction gain	402
Reorganization items, net	(35,252)
Other, net	467
Loss before income tax benefit	(358,096)
Income tax benefit	3,465
Net loss	(354,631)
Debtor [Member] | Contract Drilling [Member]
Revenues:
Total revenues	119,133
Operating expenses:
Contract drilling, excluding depreciation	130,268
Debtor [Member] | Reimbursable Expenses [Member]
Revenues:
Total revenues	12,264
Operating expenses:
Contract drilling, excluding depreciation	$ 11,837