Convertible Senior Notes (Tables)

6 Months Ended

Jun. 30, 2015

Debt Disclosure [Abstract]

Carrying Value of 2018 Convertible Notes

The carrying value of the 2018 Convertible Notes as of June 30, 2015 is summarized as follows:

Principal amount	$	120,000
(Less): Unamortized debt discount (amortized through December 2018)	(21,134		)
June 30, 2015	$	98,866

Components of the Interest Expense Recognized

The following table sets forth the components of interest expense (excluding nominal interest income) recognized in the accompanying Condensed Consolidated Statements of Operations for the 2018 Convertible Notes for the six months ended June 30, 2015:

Contractual coupon interest expense	$	1,650
Amortization of debt issuance costs	327
Accretion of debt discount	2,569
Total	$	4,546
Effective interest rate	8.66		%