Note 7 – Long-Term Debt

Convertible Notes

The Company incurred approximately $10.0 million of debt issuance costs during the first quarter of 2016 relating to the issuance of $325 million aggregate principal amount of convertible senior unsecured notes that will mature on February 1, 2023 (the “Notes”), which were recorded as a reduction to the Notes on the consolidated balance sheet. The $10.0 million of debt issuance costs is being amortized and recognized as additional interest expense over the seven-year contractual term of the Notes on a straight-line basis, which approximates the effective interest rate method.

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

	March 31, 2018		December 31, 2017
Principal amount of Notes	$	325,000	$	325,000
Unamortized debt issuance costs		(6,881)		(7,237)
Total convertible notes payable	$	318,119	$	317,763

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

	Three Months Ended March 31,
	2018		2017
Coupon interest at 3.75%	$	3,047	$	3,047
Amortization of debt issuance costs		356		356
Total interest expense on Notes	$	3,403	$	3,403