A summary of long-term debt and capital leases by debt instrument follows:



	June 30, 2017		December 31, 2016
Senior Secured Credit Facility:
Revolving Credit Facility due October 2021; bearing interest at LIBOR plus 2.75% and 3.00%, respectively	$	55,600	$	62,600
Term Loan B Facility due October 2023; bearing interest at LIBOR plus 2.75% and 3.00%, respectively	348,250		350,000
Tax-Exempt Bonds:
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014 due December 2044 - fixed rate interest period through 2019; bearing interest at 3.75%	25,000		25,000
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014R-2 due December 2044 - fixed rate interest period through 2026; bearing interest at 3.125%	15,000		15,000
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 due January 2025 - fixed rate interest period through 2025; bearing interest at 5.25%	25,000		—
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015 due August 2035 - fixed rate interest period through 2025; bearing interest at 5.125%	15,000		15,000
Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2013 due April 2036 - fixed rate interest period through 2018; bearing interest at 4.75%	16,000		16,000
Business Finance Authority of the State of New Hampshire Solid Waste Disposal Revenue Bonds Series 2013 due April 2029 - fixed rate interest period through 2019; bearing interest at 4.00%	11,000		11,000
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-2 due January 2025 - fixed rate interest period through 2017; bore interest at 6.25%	—		21,400
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-1; letter of credit backed due January 2025 - bore interest at SIFMA Index	—		3,600
Other:
Capital leases maturing through April 2023; bearing interest at up to 7.70%	5,363		5,534
Notes payable maturing through June 2027; bearing interest at up to 7.00%	2,945		449
Principal amount of long-term debt and capital leases	519,158		525,583
Less—unamortized discount and debt issuance costs (1)	16,550		16,936
Long-term debt and capital leases less unamortized discount and debt issuance costs	502,608		508,647
Less—current maturities of long-term debt	5,016		4,686
	$	497,592	$	503,961


(1)	A summary of unamortized discount and debt issuance costs by debt instrument follows:



	June 30, 2017		December 31, 2016
Revolving Credit Facility	$	4,452	$	4,965
Term Loan B Facility (including unamortized discount of $1,598 and $1,712)	7,970		7,718
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014	1,128		1,221
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014R-2	541		571
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3	645		—
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015	726		760
Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2013	589		605
Business Finance Authority of the State of New Hampshire Solid Waste Disposal Revenue Bonds Series 2013	499		563
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-1	—		31
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-2	—		502
	$	16,550	$	16,936