Revenue from Contracts with Customers - Summary of Specified Types of Revenue Expected to be Recognized in Future Related to Unsatisfied Performance Obligations (Detail) $ in Thousands	Jun. 30, 2021 USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	$ 54,599
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 months
Revenue remaining performance obligation	$ 18,772
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue remaining performance obligation	$ 26,305
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue remaining performance obligation	$ 9,039
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue remaining performance obligation	$ 483
Mobilization and Contract Preparation Revenue [Member]
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	10,162
Mobilization and Contract Preparation Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	2,028
Mobilization and Contract Preparation Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	4,002
Mobilization and Contract Preparation Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	3,917
Mobilization and Contract Preparation Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	215
Capital Modification Revenue [Member]
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	42,338
Capital Modification Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	14,645
Capital Modification Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	22,303
Capital Modification Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	5,122
Capital Modification Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	268
Demobilization and Other Deferred Revenue [Member]
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	2,099
Demobilization and Other Deferred Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation	$ 2,099