Financial Instruments and Fair Value Disclosures - Assets Measured at Fair Value on Nonrecurring and Recurring Basis (Parenthetical) (Detail) $ in Thousands	3 Months Ended		4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($) Rig	Mar. 31, 2020 USD ($)	Apr. 23, 2021 USD ($) Rig	Dec. 31, 2021 USD ($) Rig	Dec. 31, 2020 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loss on impairment of assets | $			$ 197,027	$ 132,449	$ 842,016
Number of semisubmersible rigs | Rig			1	2
Number of rigs impaired during period | Rig	1		1	2
Four Semisubmersible Rigs [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loss on impairment of assets | $	$ 68,000	$ 774,000