Impairment of Assets - Additional Information (Detail)	2 Months Ended	3 Months Ended		4 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2021 USD ($)	Mar. 31, 2021 Rig	Mar. 31, 2020 Rig	Apr. 23, 2021 USD ($)	Jun. 30, 2021 Rig	Jun. 30, 2020 USD ($)	Dec. 31, 2020 Rig
Schedule Of Asset Impairment Charges [Line Items]
Impairment of asset | $				$ 197,027,000		$ 774,028,000
Number of rigs impaired during period		1					1
2021 Impaired Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of rigs evaluated for impairment		3			4
Number of rigs not impaired during period					4
Impairment of asset | $	$ 0			$ 197,000,000.0
Number of rigs impaired during period		1
2020 Impaired Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of rigs evaluated for impairment			5
Impairment of asset | $						$ 774,000,000.0
Number of rigs impaired during period			4