The table below reflects long-term debt and capital lease obligations outstanding as of the dates indicated:



	June 30,			December 31,
In thousands	2018			2017
Senior Secured Bank Credit Agreement	$	415,000		$	475,000
9% Senior Secured Second Lien Notes due 2021	614,919			614,919
9¼% Senior Secured Second Lien Notes due 2022	455,668			381,568
3½% Convertible Senior Notes due 2024	—			84,650
6⅜% Senior Subordinated Notes due 2021	203,545			215,144
5½% Senior Subordinated Notes due 2022	314,662			408,882
4⅝% Senior Subordinated Notes due 2023	307,978			376,501
Pipeline financings	186,525			192,429
Capital lease obligations	15,906			26,298
Total debt principal balance	2,514,203			2,775,391
Future interest payable⁽¹⁾	292,591			316,818
Debt issuance costs	(5,812		)	(7,935		)
Total debt, net of debt issuance costs	2,800,982			3,084,274
Less: current maturities of long-term debt⁽¹⁾	(111,335		)	(105,188		)
Long-term debt and capital lease obligations	$	2,689,647		$	2,979,086

(1)

Future interest payable represents most of the interest due over the terms of our 9% Senior Secured Second Lien Notes due 2021 (the “2021 Senior Secured Notes”), 9¼% Senior Secured Second Lien Notes due 2022 (the “2022 Senior Secured Notes”), and to a lesser extent our previously outstanding 3½% Convertible Senior Notes due 2024 (the “2024 Convertible Senior Notes”) and has been accounted for as debt in accordance with FASC 470-60, Troubled Debt Restructuring by Debtors. Our current maturities of long-term debt as of June 30, 2018 include $84.9 million of future interest payable related to the 2021 Senior Secured Notes and 2022 Senior Secured Notes that is due within the next twelve months. See January 2018 Note Exchanges below for further discussion.