XML 58 R45.htm IDEA: XBRL DOCUMENT v3.20.1
Convertible Senior Notes - Due 2022 - Terms (Details) - 2022 Notes
Jun. 27, 2017
USD ($)
item
D
$ / shares
Mar. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Convertible Senior Notes      
Face amount | $ $ 275,000,000 $ 274,970,000 $ 274,995,000
Interest rate (as a percent) 3.00%    
Net proceeds from offering | $ $ 263,700,000    
Offering costs | $ 11,300,000    
Principal multiple amount used in the conversion of the debt instrument | $ $ 1,000    
Convertible debt, conversion rate 22.7247    
Convertible debt, conversion price (in dollars per share) | $ / shares $ 44.00    
Trading day observation period used to determine the amount of cash and shares, if any, that are due upon conversion | item 25    
Debt term 5 years 6 months    
Convertible debt, equity component | $ $ 62,400,000    
At any time prior to close of business on the business day immediately preceding June 15, 2022      
Convertible Senior Notes      
Principal multiple amount used in the conversion of the debt instrument | $ $ 1,000    
Convertible debt, threshold, trading days | D 20    
Convertible debt, threshold, consecutive trading days | D 30    
Minimum percentage of common stock price as a percentage of the conversion price 130.00%    
Convertible debt, number of business days, measurement period | D 5    
Convertible debt, number of consecutive trading days, measurement period | D 10    
Trading price expressed as a percentage of the last reported sales price and conversion rate after the specified consecutive trading day period 98.00%    
On or after December 22, 2020      
Convertible Senior Notes      
Convertible debt, threshold, trading days | D 20    
Convertible debt, threshold, consecutive trading days | D 30    
Minimum percentage of common stock price as a percentage of the conversion price 130.00%