Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Additional Information (Detail)

v3.20.4
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
May 25, 2017
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of shares authorized       18,650,000  
Number of shares, outstanding   3,785,941 5,318,759 6,839,417 6,342,526
Number of shares available for grant   1,000,000 2,300,000    
Options, aggregate intrinsic value   $ 146.3      
Options, exercisable, intrinsic value   $ 71.9      
Common stock closing price (in dollars per share)   $ 53.84      
Options outstanding and exercisable (in shares)   1,600,000      
Options exercised during period, intrinsic value   $ 68.6 $ 35.3 $ 29.3  
Proceeds from stock options exercised   18.4 12.4 8.6  
Fair value of options granted   7.5 5.6 6.9  
Fair value of options vested   $ 5.2 $ 5.5 $ 5.5  
Common stock issuance ESPP plan (in shares)   138,309 141,908 113,503  
Employee Stock Option          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense   $ 6.0 $ 6.8 $ 5.4  
Unrecognized stock based compensation   $ 5.7      
Unrecognized stock based compensation, weighted average period   1 year 10 months 24 days      
Employee Stock Purchase Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense   $ 0.9 0.6 0.2  
Discount from market price (as a percent) 15.00%        
Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense   3.4 $ 2.6 $ 1.3  
Unrecognized stock based compensation   $ 3.3      
Unrecognized stock based compensation, weighted average period   1 year 9 months 18 days      
Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period   3 years      
Minimum | Employee Stock Option          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Expiration period   5 years      
Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period   4 years      
Maximum | Employee Stock Option          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Expiration period   7 years