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Intangible Assets - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Intangible Assets Net Excluding Goodwill [Abstract]          
Impairment losses of intangible assets   $ 0   $ 0  
Amortization expense $ 1,000,000.0   $ 1,300,000 $ 3,400,000 $ 4,000,000.0