Quarterly report pursuant to Section 13 or 15(d)

Debt Instruments (Tables)

v3.10.0.1
Debt Instruments (Tables)
 9 Months Ended
Sep. 30, 2018
Debt Disclosure [Abstract]  
Schedule of long-term debt Long-term debt, net consisted of the following:

 
As of December 31,
 
As of September 30,
 
2017
 
2018
 
(in thousands)
1.75% convertible senior notes due 2020
$
345,000

 
$
152,100

Unamortized discount and deferred issuance costs
(71,986
)
 
(24,453
)
Carrying value of 1.75% convertible senior notes due 2020
$
273,014

 
$
127,647

1.75% convertible senior notes due 2023
—

 
192,900

Unamortized discount and deferred issuance costs
—

 
(65,275
)
Carrying value of 1.75% convertible senior notes due 2023
$
—

 
$
127,625

Long-term debt, net
$
273,014

 
$
255,272

Summary of the effective interest rate, contractually stated interest expense and costs related to amortization of discount for the Notes The following tables outlines the effective interest rate, contractually stated interest expense and costs related to the amortization of the discount for the Notes:

 
Three months ended 
 September 30,
 
2017
 
2018
 
2017
 
2018
 
2020 Notes
 
2023 Notes
 
(in thousands except for effective interest rate)
Effective interest rate
10.18
%
 
10.18
%
 
N/A
 
10.38
%
Contractually stated interest expense
$
1,509

 
$
691

 
N/A
 
$
844

Amortization of discount
$
5,135

 
$
2,593

 
N/A
 
$
2,381



 
Nine months ended 
 September 30,
 
2017
 
2018
 
2017
 
2018
 
2020 Notes
 
2023 Notes
 
(in thousands except for effective interest rate)
Effective interest rate
10.18
%
 
10.18
%
 
N/A
 
10.38
%
Contractually stated interest expense
$
4,511

 
$
3,320

 
N/A
 
$
1,191

Amortization of discount
$
14,934

 
$
12,031

 
N/A
 
$
3,360