The following table summarizes the Company’s long-term debt:


	June 30,			December 31,
	2022			2021
4.75% Convertible Senior Notes, due June 1, 2042	$	172,500		$	—
4.25% Convertible Senior Notes, due March 1, 2037		23,916			23,916
3.90% Promissory Note, due through April 1, 2032		9,253			9,431
3.75% Callable Promissory Note, due through September 1, 2036		7,060			7,246
4.55% Promissory Note, due through August 1, 2036		5,098			5,225
Finance lease liabilities, due through October 15, 2024		21			31
Total principal amount		217,848			45,849
Less: unamortized issuance costs		(6,200	)		(345	)
Total long-term debt	$	211,648		$	45,504

The following table summarizes future maturities of long-term debt as of June 30, 2022, which takes into consideration the assumption that the 4.75% Convertible Senior Notes and 4.25% Convertible Senior Notes are repurchased at their respective next earliest call dates:


Due in 12 months following June 30,
2022	$	1,026
2023		1,057
2024		1,096
2025		1,140
2026		197,603
Thereafter		15,926
Total	$	217,848

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


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
Interest Expense:
Contractual interest	$	1,334	$	1,704	$	1,806	$	3,411
Non-cash expense (a)		119		271		159		539
Total	$	1,453	$	1,975	$	1,965	$	3,950

(a)

Includes amortization of debt issuance costs.

In May 2022, the Company issued 4.75% Convertible Senior Notes in a private offering for an aggregate principal amount of $172,500. The net proceeds of the 4.75% Convertible Senior Notes were $166,486 after $6,014 in related issuance and transaction costs. These notes mature June 1, 2042 and the cash interest is payable semiannually in arrears on June 1 and December 1 of each year, beginning on December 1, 2022.

The 4.75% Convertible Senior Notes rank equally in right of payment to the Company’s existing and future unsecured and unsubordinated obligations. The 4.75% Convertible Senior Notes do not contain any financial or operating covenants or restrictions on the payments of dividends, the incurrence of indebtedness or

the issuance or repurchase of securities by the Company or any of its subsidiaries. The 4.75% Convertible Senior Notes provide no protection to the note holders in the event of a fundamental change or other corporate transaction involving the Company except those described in the indenture. The 4.75% Convertible Senior Notes do not require a sinking fund to be established for the purpose of redemption. In conjunction with the issuance of the 4.75% Convertible Senior Notes, the Company entered into a share repurchase agreement providing for the repurchase of shares of the Company’s common stock. See Note 18 -- “Equity” under Share Repurchase Agreement for additional information.

The conversion feature of the 4.75% Convertible Senior Notes is subject to conversion rate adjustments upon the occurrence of specified events (including payment of dividends above a specified amount) but will not be adjusted for any accrued and unpaid interest.

The conversion rate of the 4.75% Convertible Senior Notes is currently 12.4166 shares of common stock for each $1 in principal amount, which is the equivalent of approximately $80.54 per share.

The holders of the 4.75% Convertible Senior Notes may convert all or a portion of their convertible senior notes during specified periods prior to the maturity date as follows: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2022, if the last reported sale price of the Company’s common stock for at least 20 trading days during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; (2) during the five business-day period after any ten consecutive trading-day period in which the trading price per $1 principal amount of the 4.75% Convertible Senior Notes is less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; (3) if specified corporate events, including a change in control, occur; (4) if any or all of the 4.75% Convertible Senior Notes are called for redemption, at any time prior to the close of business on the business day prior to the redemption date; or (5) during either the period beginning on, and including, March 1, 2027 and ending at the close of business on the business day immediately preceding June 7, 2027, or the period beginning on, and including, March 1, 2042 and ending at the close of business on the business day immediately preceding the maturity date.

The note holders who elect to convert their convertible senior notes in connection with a fundamental change as described in the indenture will be entitled to a “make-whole” adjustment in the form of an increase in the conversion rate. Upon conversion, the Company has the option to satisfy its conversion obligation by paying or delivering cash, shares of its common stock or a combination of cash and shares of its common stock. As of June 30, 2022, none of the conditions allowing the holders of the 4.75% Convertible Senior Notes to convert had been met.

The Company determined that the 4.75% Convertible Senior Notes’ embedded conversion feature is not a derivative financial instrument and does not require bifurcation.

The note holders have the right to require the Company to repurchase for cash all or any portion of the 4.75% Convertible Senior Notes at par prior to the maturity date should any of the fundamental change events described in the indenture occur. The Company concluded that this embedded redemption feature is not a derivative financial instrument, does not require bifurcation, and that it is not probable at issuance that any of the

specified fundamental change events will occur. Therefore, this embedded redemption feature is not substantive and will not affect the expected life of the liability.

At the option of the holders of the 4.75% Convertible Senior Notes, the Company is required to repurchase for cash all or any portion of the 4.75% Convertible Senior Notes at par on June 1, 2027, June 1, 2032 or June 1, 2037. The Company concluded that this embedded feature is not a derivative financial instrument and does not require bifurcation. Due to this provision, the Company determined that it is appropriate to amortize the debt issuance costs from the date the debt is issued to the earliest date at which the holders of the 4.75% Convertible Senior Notes can demand payment. Thus, the Company amortizes the issuance costs associated with the 4.75% Convertible Senior Notes over the period from May 23, 2022 to June 1, 2027.

The effective interest rate for the 4.75% Convertible Senior Notes, taking into account both cash and non-cash components, approximates 5.6%. Had a 20-year term been used for the amortization of the issuance costs of the 4.75% Convertible Senior Notes, the annual effective interest rate charged to earnings would have decreased to approximately 5.0%. As of June 30, 2022, the remaining amortization period of the debt issuance costs was expected to be 4.9 years for the 4.75% Convertible Senior Notes.

On March 1, 2022, none of the holders of the 4.25% Convertible Senior Notes exercised the put option, which would have required the Company to repurchase for cash all or any portion of the notes at par. 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 Senior Notes. Accordingly, as of June 30, 2022, the conversion rate of the Company’s 4.25% Convertible Senior Notes was 16.4976 shares of common stock for each $1 in principal amount, which was the equivalent of approximately $60.61 per share.

The debt issuance costs for the 4.25% Convertible Senior Notes had been fully amortized as of February 2022.