Annual report pursuant to Section 13 and 15(d)

Issuance of 6.25% Convertible Sr. Notes due 2026 (Details)

v3.20.4
Issuance of 6.25% Convertible Sr. Notes due 2026 (Details)
$ in Millions
3 Months Ended 12 Months Ended
Feb. 01, 2021
USD ($)
Mar. 31, 2017
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
Maturity Year 2022        
Subsequent Event [Line Items]        
Proceeds from convertible senior notes   $ 282.2    
Convertible senior notes conversion ratio     0.0632040 0.0631793
Convertible Debt [Member] | Maturity Year 2022        
Subsequent Event [Line Items]        
Aggregate principal amount     $ 287.5  
Convertible senior notes interest rate per annum     6.25%  
Subsequent Event [Member] | Maturity Year 2026        
Subsequent Event [Line Items]        
Convertible senior notes conversion ratio 0.1355014      
Subsequent Event [Member] | Convertible Debt [Member] | Maturity Year 2026        
Subsequent Event [Line Items]        
Aggregate principal amount $ 287.5      
Proceeds from convertible senior notes $ 279.9      
Convertible senior notes interest rate per annum 6.25%      
Subsequent Event [Member] | Convertible Debt [Member] | Maturity Year 2022        
Subsequent Event [Line Items]        
Aggregate principal amount $ 143.7      
Convertible senior notes interest rate per annum 6.25%      
Subsequent Event [Member] | Convertible Debt [Member] | Over-Allotment Option [Member] | Maturity Year 2026        
Subsequent Event [Line Items]        
Aggregate principal amount $ 37.5