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Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]      
Intangible assets amortization expense $ 9,700,000 $ 12,700,000  
Changes in carrying amount of goodwill 0    
Carrying amount of goodwill $ 1,007,968,000   $ 1,007,968,000