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Common Stock Repurchase Programs - Additional Information (Detail) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Aug. 31, 2018
Common Stock [Line Items]      
Stock repurchased during period, shares 0    
Common stock authorized for repurchase     $ 500.0
Company's Common stock remained available for repurchase   $ 98.7  
Restricted Stock [Member]      
Common Stock [Line Items]      
Number of shares withheld to satisfy minimum statutory tax withholding obligations 200,000    
Amount withheld to satisfy minimum statutory tax withholding obligations $ 4.7