XML 71 R60.htm IDEA: XBRL DOCUMENT v3.20.2
Convertible Senior Notes - Additional Information (Details)
1 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2019
USD ($)
$ / shares
shares
Nov. 30, 2017
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2018
d
Sep. 30, 2020
USD ($)
d
$ / shares
Dec. 31, 2019
USD ($)
$ / shares
0.125% Convertible Senior Notes Due 2024            
Debt Instrument [Line Items]            
Aggregate principal amount $ 450,000,000   $ 450,000,000   $ 450,000,000 $ 450,000,000
Debt instrument, interest rate 0.125%   0.125%   0.125% 0.125%
Debt instrument, maturity date Dec. 15, 2024       Dec. 15, 2024  
Debt instrument, interest rate terms         Interest is payable semiannually in arrears on June 15 and December 15 of each year, commencing on June 15, 2020.  
Interest payment commencing date Jun. 15, 2020          
Debt Conversion, initial conversion rate | shares 8.8999          
Principal amount per note used in conversion rate $ 1,000         $ 1,000
Conversion price per share | $ / shares $ 112.36         $ 112.36
Shares issuable upon conversion of debt | shares 4,000,000.0          
Number of trading days | d         20  
Number of consecutive trading days | d         30  
Percentage of last reported sale price to conversion price on each applicable trading day         130.00%  
Description of convertible notes at option of holders         On or after June 15, 2024 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their 2024 Notes at the conversion rate at any time regardless of whether the conditions set forth below have been met.  
Redemption price, percentage         100.00%  
Implied interest rate     5.16%   5.16%  
Debt instrument, fair value     $ 360,400,000   $ 360,400,000  
Difference between aggregate principal amount and estimated fair value of liability component recorded in additional paid-in capital         89,600,000  
Transaction costs attributable to liability component     10,200,000   10,200,000  
Transaction costs attributable to equity component     $ 2,600,000   $ 2,600,000  
Initial strike price of capped call options | $ / shares         $ 112.36  
Capped call options, cap price | $ / shares         $ 166.46  
Cost of purchased capped call options $ 44,900,000       $ 44,900,000  
Share Price | $ / shares     $ 125.73   $ 125.73  
0.125% Convertible Senior Notes Due 2024 | Scenario One            
Debt Instrument [Line Items]            
Number of trading days | d         20  
Number of consecutive trading days | d         30  
Percentage of last reported sale price to conversion price on each applicable trading day         130.00%  
0.125% Convertible Senior Notes Due 2024 | Scenario Two            
Debt Instrument [Line Items]            
Number of consecutive trading days | d         10  
Percentage of last reported sale price to conversion price on each applicable trading day         98.00%  
Notes measurement period         5 days  
1.50% Convertible Senior Notes Due 2022            
Debt Instrument [Line Items]            
Aggregate principal amount $ 92,000,000 $ 115,000,000.0 $ 90,992,000   $ 90,992,000 $ 92,000,000
Debt instrument, interest rate   1.50% 1.50%   1.50%  
Debt instrument, maturity date   Nov. 01, 2022     Nov. 01, 2022  
Debt instrument, interest rate terms         Interest is payable semiannually in arrears on May 1 and November 1 of each year, commencing on May 1, 2018  
Interest payment commencing date   May 01, 2018        
Debt Conversion, initial conversion rate | shares   29.6626        
Principal amount per note used in conversion rate   $ 1,000        
Conversion price per share | $ / shares   $ 33.71        
Shares issuable upon conversion of debt | shares   3,400,000        
Number of trading days | d       30 20  
Number of consecutive trading days | d         30  
Percentage of last reported sale price to conversion price on each applicable trading day         130.00%  
Description of convertible notes at option of holders         On or after May 1, 2022, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their 2022 Notes at the conversion rate at any time regardless of whether the conditions set forth below have been met.  
Redemption price, percentage         100.00%  
Implied interest rate     6.93%   6.93%  
Debt instrument, fair value     $ 92,100,000   $ 92,100,000  
Difference between aggregate principal amount and estimated fair value of liability component recorded in additional paid-in capital         $ 22,900,000  
Transaction costs attributable to liability component   $ 2,500,000        
Transaction costs attributable to equity component   800,000        
Initial strike price of capped call options | $ / shares         $ 33.71  
Capped call options, cap price | $ / shares         47.20  
Cost of purchased capped call options   12,900,000        
Share Price | $ / shares     $ 125.73   $ 125.73  
1.50% Convertible Senior Notes Due 2022 | Scenario One            
Debt Instrument [Line Items]            
Number of trading days | d         20  
Number of consecutive trading days | d         30  
Percentage of last reported sale price to conversion price on each applicable trading day         130.00%  
1.50% Convertible Senior Notes Due 2022 | Scenario Two            
Debt Instrument [Line Items]            
Number of consecutive trading days | d         5  
Percentage of last reported sale price to conversion price on each applicable trading day         98.00%  
Notes measurement period         5 days  
1.50% Convertible Senior Notes Due 2022 Repurchase            
Debt Instrument [Line Items]            
Debt Conversion, initial conversion rate | shares     29,898      
Principal amount per note used in conversion rate     $ 1,000,000.0   $ 1,000,000.0  
Implied interest rate 4.64%   4.64%   4.64% 4.64%
Repayments of debt           $ 57,800,000
Repurchase of aggregate principal amount $ 23,000,000.0         23,000,000.0
Loss on extinguishment of convertible notes           1,400,000
Remaining consideration allocated to reacquisition of equity component           36,700,000
Partially terminated capped call options           5,800,000
Additional paid-in capital related to shares issued     $ 900,000      
Option to Purchase | 0.125% Convertible Senior Notes Due 2024            
Debt Instrument [Line Items]            
Aggregate principal amount $ 75,000,000.0         $ 75,000,000.0
Option to Purchase | 1.50% Convertible Senior Notes Due 2022            
Debt Instrument [Line Items]            
Aggregate principal amount   $ 15,000,000.0