Debt Obligations (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Convertible Debt [Table Text Block]

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

	December 31,
	2017
Principal value, Convertible Senior Notes, due 2024	258,750
Unamortized issuance costs	(6,685	)
Unamortized discount	(55,515	)
Convertible debt	196,550

Schedule of Long-term Debt Instruments

Debt obligations consisted of the following (in thousands):

	December 31,			December 31,
	2017			2016
Unsubordinated term loan	$	70,568		$	85,636
Revolving credit facility	245,000			355,000
Aircraft loans	3,640			18,085
Convertible debt	196,550			—
Total debt obligations	515,758			458,721
Less: current portion	(18,512		)	(29,306		)
Total long term obligations, net	$	497,246		$	429,415

Schedule of Maturities of Long-term Debt

The scheduled cash principal payments for the Company's debt obligations, as of December 31, 2017, for the next five years are as follows (in thousands):

	Principal Payments
2018	$	18,640
2019	15,000
2020	15,000
2021	15,000
2022	256,250
2023 and beyond	258,750
Total principal cash payments	578,640
Less: unamortized issuance costs and discounts	(62,882		)
Total debt obligations	$	515,758