Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Additional Information (Detail)

v3.19.3.a.u2
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
May 25, 2017
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of shares authorized     18,650,000    
Number of shares, outstanding   5,318,759 6,839,417 6,342,526 5,136,110
Number of shares available for grant   2,300,000 3,300,000    
Granted   969,720 2,457,102 2,119,498  
Options, aggregate intrinsic value   $ 102.5      
Options, exercisable, intrinsic value   $ 49.2      
Common stock closing price (in dollars per share)   $ 29.25      
Options outstanding and exercisable   2,300,000      
Options exercised during period, intrinsic value   $ 35.3 $ 29.3 $ 2.8  
Proceeds from stock options exercised   12.4 8.6 2.2  
Fair value of options granted   5.6 6.9 4.8  
Fair value of options vested   $ 5.5 $ 5.5 $ 3.6  
Common stock issuance ESPP plan (in shares)   141,908 113,503 108,599  
Employee Stock Option          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense   $ 6.8 $ 5.4 $ 5.0  
Unrecognized stock based compensation   $ 4.6      
Unrecognized stock based compensation, weighted average period   1 year 6 months      
Employee Stock Purchase Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense   $ 0.6 0.2 0.1  
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   2.6 $ 1.3 $ 1.3  
Unrecognized stock based compensation   $ 2.9      
Unrecognized stock based compensation, weighted average period   1 year 4 months 24 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