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Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]      
Impairment of Goodwill $ 0 $ 0  
Amortization of Intangible Assets, Total $ 3,621,000 $ 3,399,000 $ 3,470,000