Debt and Credit Facilities (Tables)

3 Months Ended

Mar. 31, 2019

Debt Instrument [Line Items]

Schedule of carrying value of the Notes

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

	March 31, 2019			December 31, 2018
Principal amount	$	46,000		$	46,000
Unamortized debt discount - equity component	(6,410		)	(6,778		)
Unamortized debt discount - initial purchaser	(1,914		)	(2,024		)
Unamortized transaction costs	(302		)	(319		)
Net carrying value	$	37,374		$	36,879

Schedule of convertible debt interest expense

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

	Three Months Ended March 31,
	2019		2018
Cash interest expense
Coupon interest expense	$	633	$	633
Non-cash interest expense
Amortization of debt discount - equity component	368		327
Amortization of debt discount - initial purchaser	110		97
Amortization of transaction costs	17		15
Total interest expense	$	1,128	$	1,072