Quarterly report pursuant to Section 13 or 15(d)

Convertible Senior Notes - Notes Payable (Details)

v3.20.1
Convertible Senior Notes - Notes Payable (Details) - Convertible Notes - 2023 Convertible Senior Notes - USD ($)
Mar. 31, 2020
Dec. 31, 2019
May 31, 2018
Notes Payable, Current and Noncurrent [Abstract]      
Principal amount of Notes outstanding $ 515,560,000 $ 750,000,000 $ 750,000,000.0
Unamortized discount (including unamortized debt issuance cost) (71,128,000) (111,041,000)  
Total long-term portion of notes payable 444,432,000 638,959,000  
Carrying value of equity component of the 2023 Notes 64,966,000 101,422,000  
Fair value of convertible senior notes outstanding (Level 2) $ 425,662,000 $ 647,280,000