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Employee Savings Plans - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Expenses related ESOP $ 13.9 $ 12.3 $ 10.3
Shares vested under ESOP 2,996,000    
Matching percentage of employer to employee contributions 100.00%    
Matching contributions to 401(k) retirement savings plan $ 29.8 26.9 $ 26.2
Temporary equity, shares issued (in shares) 101,521    
Deferred compensation $ 11.2 12.3  
Temporary equity, other changes 10.0    
Temporary equity, accretion to redemption value, adjustment $ 1.2    
Employee Stock Ownership Plan E S O P Plan      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Maximum number of shares of common stock available for issuance 7,700,000    
Fair value, measurements, recurring      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Total assets at fair value $ 54.5    
Level 1 | Fair value, measurements, recurring      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Total assets at fair value 52.4    
Level 1 | Fair value, measurements, recurring | Non-qualified deferred compensation assets      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Total assets at fair value $ 52.4 $ 48.3  
Share-based Compensation Award, Tranche One      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
ESOP vesting period 2 years    
Share-based Compensation Award, Tranche Two      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
ESOP vesting period 3 years