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Revenue Recognition - Additional Information (Detail) - Vessel Mobilization - USD ($)
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disaggregation of Revenue [Line Items]      
Deferred costs included within other current assets and other assets   $ 4,100,000 $ 1,600,000
Other Assets      
Disaggregation of Revenue [Line Items]      
Deferred costs included within other current assets and other assets   $ 800,000 $ 0
Unsatisfied Performance Obligations | Scenario, Forecast      
Disaggregation of Revenue [Line Items]      
Deferred mobilization revenue included within other current liabilities $ 1,000,000.0