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Revenue - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
Jun. 30, 2021
USD ($)
Category
Dec. 31, 2020
USD ($)
Revenue [Line Items]      
Number of categories | Category   3  
Remaining performance obligations $ 0 $ 0  
Recognized revenue 2,900,000 7,900,000  
Other Than Maintenance Services [Member]      
Revenue [Line Items]      
Remaining performance obligations $ 19,700,000 $ 19,700,000 $ 17,700,000