Quarterly report pursuant to Section 13 or 15(d)

Debt - Summary (Details)

v3.20.2
Debt - Summary (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Aug. 31, 2020
Dec. 31, 2019
Debt Instrument [Line Items]            
Revolving credit facility balance $ 0   $ 0     $ 260,000,000
Convertible Notes due 2023            
Debt Instrument [Line Items]            
Face amount 345,000,000   345,000,000     345,000,000
Unaccreted discount on convertible notes (26,444,000)   (26,444,000)     (33,491,000)
Unamortized issuance costs on convertible notes (4,733,000)   (4,733,000)     (5,996,000)
Convertible notes carrying value $ 313,823,000   $ 313,823,000     305,513,000
Effective interest rate 6.00% 6.00% 6.00% 6.00%    
Convertible Notes due 2025            
Debt Instrument [Line Items]            
Face amount $ 517,500,000   $ 517,500,000   $ 517,500,000 0
Unaccreted discount on convertible notes (69,104,000)   (69,104,000)   $ (70,552,000) 0
Unamortized issuance costs on convertible notes (12,301,000)   (12,301,000)     0
Convertible notes carrying value $ 436,095,000   $ 436,095,000     $ 0
Effective interest rate 4.00%   4.00%