XML 66 R55.htm IDEA: XBRL DOCUMENT v3.22.1
Stock-based compensation - Additional information (Detail) - USD ($)
$ / shares in Units, $ in Millions
6 Months Ended
Sep. 01, 2020
Sep. 26, 2018
Mar. 31, 2022
Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized stock-based compensation expense, period for recognition     1 year 3 months 18 days  
Unrecognized compensation cost, stock options     $ 22.3  
Weighted average grant date fair value of stock options granted (in usd per share)     $ 73.39  
Aggregate number of common stock shares reserved for issuance     554,000 355,000
2018 ESPP        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Aggregate number of common stock shares reserved for issuance   275,225    
Minimum annual increase in share reserved for issuance   249,470    
Annual automatic Increase in share reserved for issuance (as a percent)   1.00%    
Percentage of payroll deduction to purchase common stock   15.00%    
ESPP eligible employee common stock purchase price ratio   85.00%    
Performance Stock Option | 2018 Equity Incentive Plan | Executive Officers and Senior Level Employees        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares expected to vest     256,665  
Share based compensation by share based payment arrangement equity instruments other than options non vested outstanding grant date fair value (in usd per share)     $ 45.18  
Share based compensation by share based payment arrangement equity instruments other than options unrecognized compensation     $ 2.8  
Unrecognized stock-based compensation expense, period for recognition     6 months  
Performance Stock Option | 2018 Equity Incentive Plan | Minimum | Executive Officers and Senior Level Employees        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of PSUs that may vest based on performance 0.00%      
Performance Stock Option | 2018 Equity Incentive Plan | Maximum | Executive Officers and Senior Level Employees        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of PSUs that may vest based on performance 150.00%      
Performance Stock Unit        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share based compensation by share based payment arrangement equity instruments other than options non vested outstanding grant date fair value (in usd per share)     $ 81.21 $ 3.59
Share based compensation by share based payment arrangement equity instruments other than options unrecognized compensation     $ 22.7  
Unrecognized stock-based compensation expense, period for recognition     2 years 1 month 6 days  
Performance Stock Unit | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of PSUs that may vest based on performance     0.00%  
Vesting period     1 year  
Performance Stock Unit | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of PSUs that may vest based on performance     150.00%  
Vesting period     2 years  
Restricted Stock Units (RSUs)        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share based compensation by share based payment arrangement equity instruments other than options non vested outstanding grant date fair value (in usd per share)     $ 85.41 $ 73.27
Restricted Stock Units (RSUs) | 2018 ESPP        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized stock-based compensation expense, period for recognition     3 years 1 month 6 days  
Unrecognized compensation cost, stock options     $ 114.7