Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of carrying values of the Notes

The carrying value of the Notes is as follows (in thousands):

	As of December 31, 2017
Principal amount	$	46,000
Unamortized debt discount - equity component	(8,144		)
Unamortized debt discount - initial purchaser	(2,431		)
Unamortized transaction costs	(383		)
Net carrying value	$	35,042

Schedule of convertible debt interest expense

Total interest expense related to the Notes is as follows (in thousands):

	Year ended December 31, 2017
Cash interest expense
Coupon interest expense	$	661
Non-cash interest expense
Amortization of debt discount - equity component	330
Amortization of debt discount - initial purchaser	98
Amortization of transaction costs	16
Total interest expense	$	1,105