Quarterly report pursuant to Section 13 or 15(d)

Debt - Convertible Debt (Details)

v3.8.0.1
Debt - Convertible Debt (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2017
May 31, 2017
May 23, 2017
Dec. 31, 2016
Convertible Debt [Abstract]          
Convertible notes payable, net $ 278,392 $ 278,392     $ 0
Convertible Senior Notes | Convertible Senior Notes Due November 2022          
Convertible Debt [Abstract]          
Principal amount 345,000 345,000   $ 345,000  
Unamortized discount (59,046) (59,046)      
Unamortized debt issuance costs (7,562) (7,562)      
Convertible notes payable, net 278,392 278,392 $ 282,500    
Equity component 61,390 61,390 $ 62,500    
Interest Expense, Debt [Abstract]          
Contractual interest expense 1,265 1,826      
Amortization of debt discount 2,451 3,503      
Amortization of debt issuance costs 313 447      
Interest expense, net $ 4,029 $ 5,776      
Effective interest rate of the liability component 5.87% 5.87%