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Equity Plans and Stock-Based Compensation - Fair Value-Based Measurements and Weighted-Average Assumptions (Detail) - $ / shares
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Share-based Payment Arrangement, Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Weighted-average fair value per share $ 7.91 $ 5.82 $ 6.85 $ 3.95
Expected life (in years) 4 years 6 months 4 years 6 months 4 years 6 months 4 years 6 months
Volatility 0.90% 1.00% 1.00% 0.90%
Minimum | Share-based Payment Arrangement, Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Risk-free interest rate 0.70% 0.30% 0.60% 1.10%
Market Based Performance Stock Unit        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Weighted-average fair value per share     $ 8.40  
Expected life (in years)     2 years 10 months 24 days  
Volatility     0.90%  
Market Based Performance Stock Unit | Minimum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Risk-free interest rate     0.03%  
Market Based Performance Stock Unit | Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Risk-free interest rate     1.92%