Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Debt - Narrative (Detail)

v3.21.2
Debt - Narrative (Detail)
3 Months Ended 9 Months Ended
Jan. 11, 2021
USD ($)
day
$ / shares
Rate
shares
May 04, 2020
USD ($)
day
$ / shares
Rate
Sep. 30, 2021
USD ($)
day
Rate
shares
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2021
USD ($)
Rate
shares
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2021
USD ($)
Sep. 30, 2021
Sep. 30, 2021
$ / shares
Dec. 31, 2020
USD ($)
Line of Credit Facility [Line Items]                    
Issuance of common stock, net         $ 12,110,000 $ 10,761,000        
Ownership of convertible notes (as a percent)   25.00%                
Proceeds from issuance of convertible debt, net of issuance costs         $ 334,410,000 $ 194,466,000        
Debt instrument, weighted average interest rates               5.07%   4.91%
0.25% Convertible Senior Notes due 2028 | Convertible Debt                    
Line of Credit Facility [Line Items]                    
Stated interest rate (as a percent) | Rate 0.25%   0.25%   0.25%          
Debt instrument, face amount $ 345,000,000                  
Discount on principal amount (as a percent) | Rate 97.00%                  
Discount on shares $ 10,600,000                  
Threshold trading days | day 20                  
Consecutive trading days | day 30                  
Conversion price on applicable trading day (as a percent) 130.00%                  
Convertible Notes, conversion ratio | Rate 1.51172%                  
Convertible Notes, conversion price (in dollars per share) | $ / shares $ 66.15               $ 48.24  
Dilutive effect of Convertible Notes (in shares) | shares     5,215,434   5,100,809          
Redemption price of principal (as a percent) 100.00%                  
Ownership of convertible notes (as a percent) 25.00%                  
Interest expense, contractual coupon interest     $ 200,000   $ 600,000          
Interest expense, accretion of debt discount     400,000   1,000,000          
Interest expense, amortization of debt issuance costs     $ 8,400   $ 23,700          
Effective interest rate on Convertible Notes (as a percent)         0.70%          
0.25% Convertible Senior Notes due 2028 | Convertible Debt | Level 2                    
Line of Credit Facility [Line Items]                    
Estimated fair value of debt             $ 342,400,000      
0.25% Convertible Senior Notes due 2028 | Convertible Debt | Debt Instrument, Redemption, Period One                    
Line of Credit Facility [Line Items]                    
Threshold trading days | day 20                  
Consecutive trading days | day 30                  
Conversion price on applicable trading day (as a percent) 130.00%                  
0.25% Convertible Senior Notes due 2028 | Convertible Debt | Debt Instrument, Redemption, Period Two                    
Line of Credit Facility [Line Items]                    
Threshold trading days | day 5                  
Consecutive trading days | day 5                  
Principal amount priced to investors (as a percent) | Rate 98.00%                  
1.25% Convertible Senior Notes due 2025                    
Line of Credit Facility [Line Items]                    
Dilutive effect of Convertible Notes (in shares) | shares     0 5,538,000 0 0        
1.25% Convertible Senior Notes due 2025 | Convertible Debt                    
Line of Credit Facility [Line Items]                    
Stated interest rate (as a percent)   1.25% 1.25%   1.25%     1.25%    
Debt instrument, face amount   $ 201,300,000                
Discount on principal amount (as a percent) | Rate   97.00%                
Discount on shares   $ 6,900,000                
Threshold trading days | day   20                
Consecutive trading days | day   30                
Conversion price on applicable trading day (as a percent)   130.00%                
Convertible Notes, conversion ratio | Rate   2.75198%                
Convertible Notes, conversion price (in dollars per share) | $ / shares   $ 36.34             $ 48.24  
Dilutive effect of Convertible Notes (in shares) | shares     5,538,360   5,538,360 3,112,801        
Redemption price of principal (as a percent)   100.00%                
Interest expense, contractual coupon interest     $ 600,000 $ 600,000 $ 1,900,000 $ 1,000,000        
Interest expense, accretion of debt discount     300,000 1,800,000 900,000 2,700,000        
Interest expense, amortization of debt issuance costs     $ 36,500 $ 25,600 $ 100,000 $ 44,700        
Effective interest rate on Convertible Notes (as a percent)         1.96%          
Convertible debt, if converted, value in excess of principal   $ 65,900,000                
1.25% Convertible Senior Notes due 2025 | Convertible Debt | Level 2                    
Line of Credit Facility [Line Items]                    
Estimated fair value of debt             $ 280,300,000     $ 320,900,000
1.25% Convertible Senior Notes due 2025 | Convertible Debt | Debt Instrument, Redemption, Period One                    
Line of Credit Facility [Line Items]                    
Threshold trading days | day   20 20              
Consecutive trading days | day   30 30              
Conversion price on applicable trading day (as a percent)   130.00% 130.00%              
1.25% Convertible Senior Notes due 2025 | Convertible Debt | Debt Instrument, Redemption, Period Two                    
Line of Credit Facility [Line Items]                    
Threshold trading days | day   5                
Consecutive trading days | day   5                
Principal amount priced to investors (as a percent) | Rate   98.00%                
Over-Allotment Option                    
Line of Credit Facility [Line Items]                    
Issuance of common stock, net $ 334,400,000 $ 194,500,000                
Capped Call Transactions                    
Line of Credit Facility [Line Items]                    
Proceeds from issuance of convertible debt, net of issuance costs $ 29,300,000                  
Capped call transaction, number of underlying shares | shares 5,200,000                  
Offering price per share (in dollars per share) | $ / shares $ 85.75                  
Premium on offering price (as a percent) 75.00%                  
Public offering price (in dollars per share) | $ / shares $ 49.00