					December 31,
	Weighted Average Interest Rate			Maturity	2020		2019
Term Loan		2.69	%	2024	$	12.2	$	82.5
Revolving Credit Facility		2.69	%	2024		272.0		329.4
Senior Notes due 2025		6.00	%	2025		500.0		500.0
Total debt						784.2		911.9
Less short-term debt and current maturities of long-term debt						10.1		10.2
Less unamortized debt issuance costs						8.3		10.7
Long-term debt					$	765.8	$	891.0

The Company maintains a $600.0 million senior secured revolving credit facility and a $100.0 million secured term loan facility (collectively, the “Credit Facility”), as amended. The secured term loan has a quarterly amortization of $2.5 million and the interest rate on the Credit Facility is variable and is based on LIBOR.

Borrowings under the Credit Facility are secured by a first priority lien on substantially all of the assets of Koppers Inc., Koppers Holdings Inc. and their material domestic subsidiaries. The Credit Facility contains certain covenants for Koppers Inc. and its restricted subsidiaries that limit capital expenditures, additional indebtedness, liens, dividends, investments or acquisitions. In addition, such covenants give rise to events of default upon the failure by Koppers Inc. and its restricted subsidiaries to meet certain financial ratios.

As of December 31, 2020, we had $307.8 million of unused revolving credit availability for working capital purposes after restrictions from certain letter of credit commitments and other covenants. As of December 31, 2020, $7.7 million of commitments were utilized by outstanding letters of credit.

The 2025 Notes are senior obligations of Koppers Inc., are unsecured and are guaranteed by Koppers Holdings Inc. and certain of Koppers Inc.’s domestic subsidiaries. The 2025 Notes pay interest semi-annually in arrears on February 15 and August 15 and will mature on February 15, 2025 unless earlier redeemed or repurchased. We are entitled to redeem all or a portion of the 2025 Senior Notes at a redemption price of 104.5 percent of principal value, declining to a redemption price of 101.5 percent on or after February 15, 2022 until the redemption price is equivalent to the principal value on April 15, 2023.

The indenture governing the 2025 Senior Notes includes customary covenants that restrict, among other things, the ability of Koppers Inc. and its restricted subsidiaries to incur additional debt, pay dividends or make certain other restricted payments, incur liens, merge or sell all or substantially all of the assets of Koppers Inc. or its subsidiaries or enter into various transactions with affiliates.

At December 31, 2020 the aggregate debt maturities for the next five years are as follows:


(Dollars in millions)
2021	$	10.1
2022		2.1
2023		0.0
2024		272.0
2025		500.0
Total debt	$	784.2

Unamortized debt issuance costs (net of accumulated amortization of $9.4 million and $6.8 million at December 31, 2020 and 2019, respectively) were $8.3 million and $10.7 million at December 31, 2020 and 2019, respectively, and are included as a deduction from the carrying amount of long-term debt.