Annual report pursuant to Section 13 and 15(d)

Convertible Senior Notes - Equity and Liability Components of Financing Arrangements (Details)

v3.10.0.1
Convertible Senior Notes - Equity and Liability Components of Financing Arrangements (Details) - USD ($)
Dec. 31, 2018
May 22, 2018
Dec. 31, 2017
Aug. 31, 2014
Notes Payable, Current and Noncurrent        
Carrying value of equity component of 2023 Notes $ 0   $ 18,859,000  
Convertible Notes        
Notes Payable, Current and Noncurrent        
Total current portion of notes payable 26,433,000   224,529,000  
Total long-term portion of notes payable 609,864,000   0  
Fair value of convertible senior notes outstanding (Level 2) 713,533,000   446,360,000  
Convertible Notes | 2019 Convertible Senior Notes        
Notes Payable, Current and Noncurrent        
Principal amount outstanding 27,326,000   245,000,000 $ 245,000,000.0
Unamortized discount (893,000)   (20,471,000)  
Convertible Notes | 2023 Convertible Senior Notes        
Notes Payable, Current and Noncurrent        
Principal amount outstanding 750,000,000 $ 750,000,000 0  
Unamortized discount (140,136,000)   0  
Carrying value of equity component of 2023 Notes $ 127,997,000   $ 0