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Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)
 3 Months Ended 12 Months Ended
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]      
Amortization expense of intangible assets   $ 36,100,000 $ 40,900,000
Estimated Future Amortization Expense by Fiscal Year [Abstract]      
2018   33,300,000  
2019   28,300,000  
2020   25,700,000  
2021   25,000,000.0  
2022   25,000,000.0  
After 2022   214,800,000  
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill) $ 108,900,000 (108,900,000)  
Goodwill, Impairment Loss 270,300,000 270,300,000 0
Deferred Income Taxes and Tax Credits $ 90,300,000    
Accumulated amortization   $ 9,500,000 $ 7,800,000