Quarterly report pursuant to Section 13 or 15(d)

Stockholders Equity and Stock Compensation - Additional Information (Detail)

v3.22.2.2
Stockholders Equity and Stock Compensation - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Jan. 31, 2022
Class Of Stock [Line Items]          
Stock repurchase program expiration date     Jan. 31, 2025    
Remaining to repurchase shares under Share Repurchase Program $ 425.8   $ 425.8    
Recognized stock compensation expense 9.7 $ 14.2 42.0 $ 39.7  
Unrecognized compensation cost related to nonvested common shares 98.0   $ 98.0    
Weighted average period for recognition of cost     2 years 3 days    
ESPP          
Class Of Stock [Line Items]          
Recognized stock compensation expense $ 0.6 $ 0.5 $ 2.1 $ 1.7  
Performance-Based Awards [Member]          
Class Of Stock [Line Items]          
Performance period     3 years    
Performance-Based Awards [Member] | Minimum [Member]          
Class Of Stock [Line Items]          
Payout percentage of performance awards     0.00%    
Performance-Based Awards [Member] | Maximum [Member]          
Class Of Stock [Line Items]          
Payout percentage of performance awards     200.00%    
Two Thousand Seventeen Plan | Performance-Based Awards [Member]          
Class Of Stock [Line Items]          
Number of shares that remain available for grant 2,782,132   2,782,132    
Two Thousand Seventeen Plan | Performance-Based Awards [Member] | Maximum [Member]          
Class Of Stock [Line Items]          
Number of shares that remain available for grant 2,082,132   2,082,132    
2018 ESPP [Member]          
Class Of Stock [Line Items]          
Number of shares available for sale under employee stock purchase plan 3,914,503   3,914,503    
Percentage of price of common stock purchased     85.00%    
Maximum percentage of employee's compensation to purchase common stock 15.00%   15.00%    
Class A Common Stock [Member]          
Class Of Stock [Line Items]          
Stock repurchase program authorized amount         $ 500.0
Class A Common Stock [Member] | 2018 ESPP [Member]          
Class Of Stock [Line Items]          
Number of shares available for sale under employee stock purchase plan 5,000,000   5,000,000