Debt Obligations - (Tables)

3 Months Ended

Mar. 31, 2015

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, 2015		December 31, 2014
Convertible senior notes	$	60,000	$	60,000
Less: Unamortized interest discount	4,416		5,227
Net carrying value of convertible senior notes	$	55,584	$	54,773

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, 2015 and March 31, 2014.

	Three Months Ended March 31,
	2015		2014
Contractual interest coupon	$	562	$	562
Amortization of interest discount	811		735
Amortization of debt issuance costs	103		87
Total interest cost recognized	$	1,476	$	1,384