Impairment of Assets - Additional Information (Detail)	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($) Rig	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Schedule Of Asset Impairment Charges [Line Items]
Loss on impairment of assets		$ 27,225,000	$ 27,225,000
Number of rigs not evaluated for impairment | Rig	10
2019 Impaired Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of rigs evaluated for impairment | Rig	3
Loss on impairment of assets	$ 0
2018 Impaired Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Loss on impairment of assets				$ 27,200,000
Impaired long-lived assets held and used, method for determining fair value				We estimated the fair value of the impaired jack-up rig using a market approach based on a signed agreement to sell the rig, less estimated costs to sell. We considered this valuation approach to be a Level 3 fair value measurement due to the level of estimation involved as the sale had not yet been completed at the time of our analysis.