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Intangible Assets - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Intangible Assets Net Excluding Goodwill [Abstract]      
Impairment losses of intangible assets $ 0 $ 0 $ 0
Amortization expense $ 4,400,000 $ 5,300,000 $ 2,300,000