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Contract Assets - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Disclosure Of Financial Instruments [Line Items]    
Advances or retentions received from construction contracts $ 0 $ 0
SDI [Member]    
Disclosure Of Financial Instruments [Line Items]    
Decrease through impairment, contract assets $ 0