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Goodwill and Intangibles - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill impairment $ 0 $ 0 $ 0
Intangible asset impairment 0 0 0
Increase in gross carrying amount of intangibles 46,400,000 28,300,000  
Intangibles on business combination 46,200,000 28,000,000.0  
Amortization of intangibles $ 28,535,000 $ 24,510,000 $ 25,419,000