	March 31,			December 31,
	2020			2019
	(In Thousands)
Working Capital Revolver Loan, with a current interest rate of 3.75% (A)	$	30,000		$	—
Senior Secured Notes due 2023 (B)		435,000			435,000
Secured Promissory Note due 2021, with an interest rate of 5.25% (C)		3,882			4,746
Secured Promissory Note due 2023, with a current interest rate of 5.17% (D)		12,210			12,705
Secured Financing due 2023, with an interest rate of 8.32% (E)		12,804			13,476
Secured Loan Agreement due 2025, with an interest rate of 8.75% (F)		7,789			5,219
Other		150			159
Unamortized discount, net of premium and debt issuance costs		(11,333	)		(12,261	)
		490,502			459,044
Less current portion of long-term debt		9,665			9,410
Long-term debt due after one year, net	$	480,837		$	449,634

(A) Our revolving credit facility (the “Working Capital Revolver Loan”) provides for advances up to $75 million, based on specific percentages of eligible accounts receivable and inventories and up to $10 million of letters of credit, the outstanding amount of which reduces the available for borrowing under the Working Capital Revolver Loan. At March 31, 2020, our available borrowings under our Working Capital Revolver Loan were approximately $20.5 million, based on our eligible collateral, less outstanding letters of credit. The maturity date of the Working Capital Revolver Loan is February 26, 2024. The Working Capital Revolver Loan also provides for a springing financial covenant (the “Financial Covenant”), which requires that, if the borrowing availability is less than 10.0% of the total revolver commitments, then the borrowers must maintain a minimum fixed charge coverage ratio of not less than 1.00 to 1.00. The Financial Covenant, if triggered, is tested monthly.

(B) On April 25, 2018, LSB completed the issuance and sale of $400 million aggregate principal amount of its 9.625% Senior Secured Notes due 2023 (the “Notes”), pursuant to an indenture (the “Indenture”), dated as of April 25, 2018. The Notes were issued at a price equal to 99.509% of their face value.

On June 21, 2019, LSB completed the issuance and sale of $35 million aggregate principal amount of its 9.625% Senior Secured Notes due 2023 (the “New Notes”). The New Notes were issued pursuant to the Indenture (the Notes together with the New Notes, the “Senior Secured Notes”). The New Notes were issued at a price equal to 102.125% of their face value, plus accrued interest from May 1, 2019 to June 21, 2019.

The Senior Secured Notes mature on May 1, 2023. Interest is to be paid semiannually in arrears on May 1^st and November 1^st.

(C) El Dorado Chemical Company (EDC), one of our subsidiaries, is party to a secured promissory note due in March 2021. Principal and interest are payable in monthly installments.

(D) El Dorado Ammonia L.L.C. (“EDA”), one of our subsidiaries, is party to a secured promissory note due in May 2023. Principal and interest are payable in equal monthly installments with a final balloon payment of approximately $6.1 million.

(E) EDC is party to a secured financing arrangement with an affiliate of LSB Funding L.L.C. (“LSB Funding”). Principal and interest are payable in 48 equal monthly installments with a final balloon payment of approximately $3 million due in June 2023.

(F) EDC is party to a secured loan agreement with an affiliate of LSB Funding, which provided for available borrowings (the “Interim Loan”) during the construction of certain equipment (the “Interim Loan Period”), subject to certain conditions. During the Interim Loan Period, interest only was payable in monthly installments. Effective February 28, 2020, the Interim Loan Period ended, and the Interim Loan was replaced by a secured promissory note due in March 2025. Under the terms of the note, principal and interest are payable in 60 equal monthly installments.