Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2018

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,
	2018			2017
Principal amount	$	46,000		$	46,000
Unamortized debt discount - equity component	(6,778		)	(8,144		)
Unamortized debt discount - initial purchaser	(2,024		)	(2,431		)
Unamortized transaction costs	(319		)	(383		)
Net carrying value	$	36,879		$	35,042

Schedule of convertible debt interest expense

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

	Years Ended December 31,
	2018		2017
Cash interest expense
Coupon interest expense	$	2,530	$	661
Non-cash interest expense
Amortization of debt discount - equity component	1,366		330
Amortization of debt discount - initial purchaser	407		98
Amortization of transaction costs	64		16
Total interest expense	$	4,367	$	1,105