Debt and Credit Facilities (Tables)

6 Months Ended

Jun. 30, 2018

Debt Instrument [Line Items]

Schedule of carrying value of the Notes

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

	June 30, 2018			December 31, 2017
Principal amount	$	46,000		$	46,000
Unamortized debt discount - equity component	(7,481		)	(8,144		)
Unamortized debt discount - initial purchaser	(2,234		)	(2,431		)
Unamortized transaction costs	(352		)	(383		)
Net carrying value	$	35,933		$	35,042

Schedule of convertible debt interest expense

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

	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Cash interest expense
Coupon interest expense	$	632	$	1,265
Non-cash interest expense
Amortization of debt discount - equity component	335		662
Amortization of debt discount - initial purchaser	101		198
Amortization of transaction costs	16		31
Total interest expense	$	1,084	$	2,156