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Equity Plans and Stock-Based Compensation - Fair Value-Based Measurements and Weighted-Average Assumptions (Detail) - $ / shares
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Share-based Payment Arrangement, Option    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Weighted-average fair value per share $ 6.72 $ 3.58
Expected life (in years) 4 years 6 months 4 years 6 months
Volatility 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 0.50% 1.40%
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 25 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%