	September 30,			December 31,
	2020			2019
4.25% Convertible senior notes, due March 1, 2037	$	139,200		$	143,750
3.95% Promissory note, due through February 17, 2020		—			8,881
4% Promissory note, due through July 29, 2020		—			7,345
3.75% Callable promissory note, due through September 1, 2036		7,695			7,955
4.55% Promissory note, due through August 1, 2036		5,529			5,704
3.90% Promissory note, due through April 1, 2032		9,861			—
Finance lease liabilities, due through August 15, 2023		48			60
Total principal amount		162,333			173,695
Less: unamortized discount and issuance costs		(6,658	)		(10,000	)
Total long-term debt	$	155,675		$	163,695

The following table summarizes future maturities of long-term debt as of September 30, 2020, which takes into consideration the assumption that the 4.25% Convertible Senior Notes are repurchased at the earliest call date.

Due in 12 months following September 30,
2020	$	960
2021		140,198
2022		1,034
2023		1,063
2024		1,106
Thereafter		17,972
Total	$	162,333

Information with respect to interest expense related to long-term debt is as follows:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2020			2019			2020			2019
Interest Expense:
Contractual interest	$	1,736		$	1,835		$	5,374		$	6,229
Non-cash expense (a)		1,053			1,018			3,174			3,807
Capitalized interest (b)		(41	)		(78	)		(125	)		(236	)
	$	2,748		$	2,775		$	8,423		$	9,800

4.25% Convertible Notes. The Company’s recent cash dividends on common stock have exceeded $0.35 per share, resulting in adjustments to the conversion rate of the 4.25% Convertible Notes. Accordingly, as of September 30, 2020, the conversion rate of the Company’s 4.25% Convertible Notes was 16.42 shares of common stock for each $1 in principal amount, which was the equivalent of approximately $60.91 per share. In June 2020, the Company repurchased an aggregate of $4,550 in principal of the 4.25% Convertible Notes and recognized a $150 loss from the repurchases.

As of September 30, 2020, the remaining amortization period of the debt discount for 4.25% Convertible Notes was expected to be 1.4 years.

On July 29, 2020, the Company made an early repayment of its 4% Promissory Note totaling $7,062 in principal plus accrued interest. As a result, the Company incurred $98 of loss on extinguishment of debt. The note was collateralized by the Company’s Tampa, Florida headquarters which was acquired by the FDOT in the eminent domain proceedings as described in Note 9 – “Property and Equipment, Net.”

In February 2020, the Company repaid its 3.95% Promissory Note for $8,891 including principal and unpaid interest payable at maturity date.

On February 28, 2020, the Company entered into a loan agreement with American Equity Investment Life Insurance Company for gross proceeds of $10,000. The agreement bears interest at a fixed rate of 3.90% and is secured by the Company’s shopping center property in Melbourne, Florida and the assignment of associated lease agreements. Approximately $60 of principal and interest is payable in 143 monthly installments beginning April 1, 2020 plus a final balloon payment of $5,007 including principal and unpaid interest payable on March 1, 2032. The promissory note may be repaid in full at any time as long as the Company provides at least 60 days’ written notice and pays a prepayment premium and processing fee. The proceeds were primarily used to repay the 3.95% Promissory Note due in February 2020.

On March 19, 2020, the loan agreement was modified to revise the due dates for the first and last installments to May 1, 2020 and April 1, 2032, respectively, while other terms and conditions remain intact.