Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2017

Debt Disclosure [Abstract]

Notes Payable

Total convertible notes payable consisted of the following at (in thousands):

	June 30, 2017		December 31, 2016
Principal amount of Notes	$	325,000	$	325,000
Unamortized debt issuance costs		(7,949)		(8,661)
Total convertible notes payable	$	317,051	$	316,339

Interest Expense

Interest expense incurred in connection with the Notes consisted of the following (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
Coupon interest	$	3,047	$	3,047	$	6,094	$	5,146
Amortization of debt issuance costs		356		356		712		593
Total interest expense on Notes	$	3,403	$	3,403	$	6,806	$	5,739