Debt Obligations (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Convertible Debt [Table Text Block]

The carrying value of the Company's Convertible debt is shown below:

	June 30,		December 31,
	2018		2017
Principal value, Convertible Senior Notes, due 2024	258,750		258,750
Unamortized issuance costs	(6,255	)	(6,685	)
Unamortized discount	(51,843	)	(55,515	)
Convertible debt	200,652		196,550

Schedule of Long-term Debt Instruments

Debt obligations consisted of the following (in thousands):

	June 30,			December 31,
	2018			2017
Unsubordinated term loan	$	63,061		$	70,568
Revolving credit facility	257,000			245,000
Aircraft loans	—			3,640
Convertible debt	200,652			196,550
Total debt obligations	520,713			515,758
Less: current portion	(14,860		)	(18,512		)
Total long term obligations, net	$	505,853		$	497,246