Debt Obligations - (Tables)

3 Months Ended

Mar. 31, 2016

Debt Obligations [Abstract]

Schedule of carrying value of convertible senior notes [Table Text Block]

The following table reflects the net carrying value of the Notes:

	March 31, 2016		December 31, 2015
Convertible senior notes	$	60,000	$	60,000
Less: Unamortized interest discount	999		1,893
Less: Unamortized debt issuance costs	138		261
Net carrying value of convertible senior notes	$	58,863	$	57,846

Schedule of interest cost recognized on convertible senior notes [Table Text Block]

The following table presents the amount of interest cost recognized relating to the Notes during the three months endedMarch 31, 2016 and March 31, 2015:

	Three Months Ended March 31,
	2016		2015
Contractual interest coupon	$	562	$	562
Amortization of interest discount	894		811
Amortization of debt issuance costs	123		103
Total interest cost recognized	$	1,579	$	1,476