XML 133 R119.htm IDEA: XBRL DOCUMENT v3.21.1
Contract Assets - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Jan. 01, 2019
Disclosure Of Financial Instruments [Line Items]      
Advances or retentions received from construction contracts $ 0 $ 0  
Receivables from contracts with customers, balance     $ 1,510,000
SDI [Member]      
Disclosure Of Financial Instruments [Line Items]      
Decrease through impairment, contract assets $ 0