Debt (Tables)

6 Months Ended

Jun. 30, 2017

Schedule of outstanding debt obligations

Our outstanding debt obligations as of June 30, 2017 and December 31, 2016 consisted of the following (in thousands):



	June 30, 2017		December 31, 2016
2023 Senior Notes	$	490,210	$	489,612
2022 Convertible Notes	241,797		—
2019 Convertible Notes	37,749		179,363
2015 Term Loan Facility	—		317,546
Total long-term debt	769,756		986,521
Less: current maturities	—		21,166
Long-term debt, net of current maturities	$	769,756	$	965,355

Schedule of outstanding convertible debt

The outstanding balances of our Convertible Notes as of June 30, 2017 consisted of the following (in thousands):



	2022 Convertible Notes		2019 Convertible Notes		Total
Liability component:
Principal	$	320,000	$	41,061	$	361,061
Less: debt discount and issuance costs, net	78,203		3,312		81,515
Net carrying amount	$	241,797	$	37,749	$	279,546
Equity Component	$	72,576	$	12,690	$	85,266

Schedule of total interest expense recognized related to the convertible notes

The following table sets forth total interest expense recognized related to the Convertible Notes during the three and six months ended June 30, 2017 and 2016 (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Contractual interest expense	$	1,943	$	1,250	$	3,193	$	2,500
Amortization of debt issuance costs	321		265		596		524
Amortization of debt discount	2,716		1,867		4,644		3,682
Total interest expense	$	4,980	$	3,382	$	8,433	$	6,706

Schedule of future annual principal payments on long-term debt

Future annual principal payments on our long-term debt as of June 30, 2017 were as follows (in thousands):



Period	Future Annual Principal Payments
Remainder of Year Ending December 31, 2017	$	—
Year Ending December 31, 2018	—
Year Ending December 31, 2019	41,061
Year Ending December 31, 2020	—
Year Ending December 31, 2021	—
Thereafter	820,000
Total	$	861,061