
	December 31, 2021		September 30, 2021
5.625% Senior Notes due 2026, net of deferred issuance costs of $3.1 million and $3.2 million, respectively. Effective interest rate 5.625%.	$	496,918	$	496,764
1.000% Convertible Debentures due 2035, net of unamortized discount of $5.5 million and $7.0 million, respectively, and deferred issuance costs of $0.3 million and $0.3 million, respectively. Effective interest rate 5.622%.	122,185		122,948
1.250% Convertible Debentures due 2025, net of unamortized discount of $33.6 million and $36.1 million, respectively, and deferred issuance costs of $1.4 million and $1.5 million, respectively. Effective interest rate 5.578%.	226,484		225,067
1.500% Convertible Debentures due 2035, net of unamortized discount of $0.1 million, as of September 30, 2021. Effective interest rate 5.394%.	—		24,984
Deferred issuance costs related to our Revolving Credit Facility	(1,733)		(1,839)
Total debt	843,854		867,924
Less: current portion (a)	(348,669)		(372,999)
Total long-term debt	$	495,185	$	494,925

The following table summarizes the maturities of our borrowing obligations as of December 31, 2021 (dollars in thousands):


Fiscal Year	Convertible Debentures (a)		Senior Notes		Total
2022	$	389,392			$	389,392
2023	—		—		—
2024	—		—		—
2025	—		—		—
2026	—		—		—
Thereafter	—		500,000		500,000
Total before unamortized discount	389,392		500,000		889,392
Less: unamortized discount and issuance costs	(40,723)		(4,815)		(45,538)
Total debt	$	348,669	$	495,185	$	843,854

In December 2016, we issued $500.0 million aggregate principal amount of 5.625% Senior Notes due on December 15, 2026 (the "2026 Senior Notes") in a private placement. The proceeds from the 2026 Senior Notes were approximately $495.0 million, net of issuance costs, and we used the proceeds to repurchase a portion of our then outstanding 5.375% Senior Notes due 2020. The 2026 Senior Notes bear interest at 5.625% per year, payable in cash semi-annually in arrears.

The 2026 Senior Notes are unsecured senior obligations and are guaranteed on an unsecured senior basis by certain of our domestic subsidiaries ("Subsidiary Guarantors"). The 2026 Senior Notes and the guarantees rank equally in right of payment with all of our and the Subsidiary Guarantors’ existing and future unsecured senior debt and rank senior in right of payment to all of our and the Subsidiary Guarantors’ future unsecured subordinated debt. The 2026 Senior Notes and guarantees effectively rank junior to all our secured debt and that of the Subsidiary Guarantors to the extent of the value of the collateral securing such debt and to all liabilities, including trade payables, of our subsidiaries that have not guaranteed the 2026 Senior Notes.

In December 2015, we issued $676.5 million in aggregate principal amount of 1.0% Senior Convertible Debentures due in 2035 (the "1.0% 2035 Debentures") in a private placement. Total proceeds were $663.8 million, net of issuance costs, and we used a portion to repurchase $38.3 million in aggregate principal on our 2.75% Senior Convertible Debentures due in 2031 (the “2.75% 2031 Debentures”) and to repay the aggregate principal balance of $472.5 million on our term loan under the amended and restated credit agreement. The 1.0% 2035 Debentures bear interest at 1.0% per year, payable in cash semi-annually in arrears. In addition to ordinary interest and default additional interest, beginning with the semi-annual interest period commencing on December 15, 2022, contingent interest will accrue during any regular semi-annual interest period where the average trading price of our 1.0% 2035 Debentures for the ten trading day period immediately preceding the first day of such semi-annual period is greater than or equal to $1,200 per $1,000 principal amount of our 1.0% 2035 Debentures, in which case, contingent interest will accrue at a rate of 0.50% per annum of such average trading price. The 1.0% 2035 Debentures mature on December 15, 2035, subject to the right of the holders to require us to redeem the 1.0% 2035 Debentures on December 15, 2022, 2027, or 2032. The 1.0% 2035 Debentures are general senior unsecured obligations and rank equally in right of payment

We account separately for the liability and equity components of the 1.0% 2035 Debentures in accordance with authoritative guidance for convertible debt instruments that may be settled in cash upon conversion. The guidance requires the carrying amount of the liability component to be estimated by measuring the fair value of a similar liability that does not have an associated conversion feature and record the remainder in stockholders’ equity. At issuance, we allocated $495.4 million to long-term debt, and $181.1 million has been recorded as additional paid-in capital, which is being amortized to interest expense using the effective interest rate method through December 2022.

If converted, the principal amount of the 1.0% 2035 Debentures is payable in cash and any amounts payable in excess of the principal amount will be paid in cash or shares of our common stock, at our election. The conversion of the 1.0% 2035 Debentures will be based upon a conversion ratio of 41.4576 common shares per $1,000 principal amount, subject to adjustments. Conversion is only allowed in the following circumstances and to the following extent: (i) prior to June 15, 2035, on any date during any fiscal quarter (and only during such fiscal quarter) if the closing sale price of our common stock was more than 130% of the then current conversion price for at least 20 trading days in the period of the 30 consecutive trading days ending on the last trading day of the previous fiscal quarter; (ii) during the five consecutive business-day period following any five consecutive trading-day period in which the trading price for $1,000 principal amount of the 1.0% 2035 Debentures for each day during such five trading-day period was less than 98% of the closing sale price of our common stock multiplied by the then current conversion rate; (iii) upon the occurrence of specified corporate transactions, as described in the indenture for the 1.0% 2035 Debentures; or (iv) at the option of the holder at any time on or after June 15, 2035. Additionally, we may redeem the 1.0% 2035 Debentures, in whole or in part, on or after December 20, 2022 for cash at a price equal to 100% of the principal amount of the 1.0% 2035 Debentures to be purchased plus any accrued and unpaid interest, including any additional interest to, but excluding, the repurchase date. Each holder shall have the right, at such holder’s option, to require us to repurchase all or any portion of the 1.0% 2035 Debentures held by such holder on December 15, 2022, December 15, 2027, or December 15, 2032 at par plus accrued and unpaid interest. If we undergo a fundamental change or non-stock change of control (as described in the indenture for the 1.0% 2035 Debentures) prior to maturity, holders will have the option to require us to repurchase all or any portion of their debentures for cash at a price equal to 100% of the principal amount of the 1.0% 2035 Debentures to be purchased plus any accrued and unpaid interest.

During the third quarter of fiscal year 2021, we induced the exchange of $457.0 million notional amount of our 1.0% 2035 Debentures for $5.0 million in cash and 18.9 million shares of common stock, of which we allocated $435.1 million to debt and $567.1 million to equity. Also, in connection with the redemptions, we wrote off $32.4 million of unamortized discount and $1.4 million of unamortized costs. As a result, we recorded a $15.0 million loss associated with the redemptions, of which $3.1 million represents the inducement expense and $1.9 million represents the interest earned at the time of settlement, based upon the guidance in ASC 470-20. Additionally, as part of these redemptions we transferred non-cash consideration in the form of shares of common stock valued at $1,002.2 million.

Also, during the fourth quarter of fiscal year 2021, holders of our 1.0% 2035 Debentures exercised their right to convert $89.2 million notional amount for $89.2 million in cash and 2.1 million shares of common stock, of which we allocated $85.4 million to debt and $117.6 million to equity. Also, in connection with the conversions, we wrote off $5.6 million of unamortized discount and $0.3 million of unamortized costs. As a result, we recorded a $2.1 million loss associated with the conversions. Additionally, as part of these conversions we transferred non-cash consideration in the form of shares of common stock valued at $113.8 million.

Additionally, during the first quarter of fiscal year 2022, holders of our 1.0% 2035 Debentures exercised their right to convert $2.3 million notional amount for $2.3 million in cash and 0.1 million shares of common stock, of which we allocated $2.2 million to debt and $3.1 million to equity. Also, in connection with the conversions, we wrote off $0.1 million of unamortized discount. As a result, we recorded an immaterial loss associated with the conversions. Additionally, as part of these conversions we transferred non-cash consideration in the form of shares of common stock valued at $3.0 million. Following the redemptions, $128.0 million in aggregate principal amount of the 1.0% 2035 Debentures remained outstanding as of December 31, 2021.

As of December 31, 2021, holders have exercised their right to convert $23.5 million notional amount of our 1.0% 2035 Debentures for an estimated $23.5 million in cash and 0.5 million shares of common stock for an estimated total consideration of $53.8 million. The settlement of these conversions occurred in the second quarter of fiscal year 2022. The net carrying amount of the 1.0% 2035 Debentures was included within the current portion of long-term debt, and $5.8 million has been reclassified from permanent equity to mezzanine equity. As of December 31, 2021, the if-converted value of the 1.0% 2035 Debentures exceeded its principal amount by $165.5 million.

In March 2017, we issued $350.0 million in aggregate principal amount of 1.25% Senior Convertible Debentures due in 2025 (the "1.25% 2025 Debentures") in a private placement. The proceeds were approximately $343.6 million, net of issuance costs. We used a portion of the proceeds to repurchase 5.8 million shares of our common stock for $99.1 million and $17.8 million in aggregate principal on our 2.75% 2031 Debentures. The 1.25% 2025 Debentures bear interest at 1.25% per year, payable in cash semi-annually in arrears, beginning on October 1, 2017. The 1.25% 2025 Debentures mature on April 1, 2025. The 1.25% 2025 Debentures are general senior unsecured obligations and rank equally in right of payment with all of our existing and future unsecured, unsubordinated indebtedness and senior in right of payment to any indebtedness that is contractually subordinated to the 1.25% 2025 Debentures. The 1.25% 2025 Debentures will be effectively subordinated to indebtedness and other liabilities of our subsidiaries.

We account separately for the liability and equity components of the 1.25% 2025 Debentures in accordance with authoritative guidance for convertible debt instruments that may be settled in cash upon conversion. The guidance requires the carrying amount of the liability component to be estimated by measuring the fair value of a similar liability that does not have an associated conversion feature and record the remainder in stockholders’ equity. At issuance, we allocated $252.1 million to long-term debt, and $97.9 million has been recorded as additional paid-in capital, which is being amortized to interest expense using the effective interest rate method through April 1, 2025.

If converted, the principal amount of the 1.25% 2025 Debentures is payable in cash and any amounts payable in excess of the principal amount will be paid in cash or shares of our common stock, at our election. The conversion of the 1.25% 2025 Debentures will be based upon a conversion ratio of 50.7957 common shares per $1,000 principal amount, subject to adjustments. Conversion is only allowed in the following circumstances and to the following extent: (i) prior to October 1, 2024, on any date during any fiscal quarter (and only during such fiscal quarter) if the closing sale price of our common stock was more than 130% of the then current conversion price for at least 20 trading days in the period of the 30 consecutive trading days ending on the last trading day of the previous fiscal quarter; (ii) at any time on or after October 1, 2024; (iii) during the five consecutive business-day period immediately following any five consecutive trading-day period in which the trading price for $1,000 principal amount of the 1.25% 2025 Debentures for each day during such five trading-day period was less than 98% of the closing sale price of our common stock multiplied by the then current conversion rate; or (iv) upon the occurrence of specified corporate transactions, as described in the indenture for the 1.25% 2025 Debentures. We may not redeem the 1.25% 2025 Debentures prior to the maturity date. If we undergo a fundamental change or non-stock change of control (as described in the indenture for the 1.25% 2025 Debentures) prior to maturity, holders will have the option to require us to repurchase all or any portion of their debentures for cash at a price equal to 100% of the principal amount of the 1.25% 2025 Debentures to be purchased plus any accrued and unpaid interest.

Additionally, during the first quarter of fiscal year 2022, holders of our 1.25% 2025 Debentures exercised their right to convert $1.2 million notional amount for $1.2 million in cash and 0.04 million shares of common stock, of which we allocated $1.1 million to debt and $2.3 million to equity. Also, in connection with the conversions, we wrote off $0.2 million of unamortized discount. As a result, we recorded an immaterial loss associated with the conversions. Additionally, as part of these conversions we transferred non-cash consideration in the form of shares of common stock valued at $2.2 million. Following the redemptions, $261.4 million in aggregate principal amount of the 1.25% 2025 Debentures remained outstanding as of December 31, 2021.

The 1.25% 2025 Debentures were convertible as of December 31, 2021, as our common stock price exceeded the conversion threshold price of 130% of the applicable conversion price per share for at least 20 trading days during the 30 consecutive trading days ending December 31, 2021. As a result, the holders of our 1.25% 2025 Debentures have the right to convert all or any portion of their debentures between January 1, 2022 and March 31, 2022. The holders previously had the right to convert all or any portion of their debentures at the aforementioned conversion ratio beginning October 1, 2020 through December 31, 2021. As of December 31, 2021, the net carrying amount of the 1.25% 2025 Debentures was included within the current portion of long-term debt, and $34.9 million has been reclassified from permanent equity to mezzanine equity. As of December 31, 2021, the if-converted value of the 1.25% 2025 Debentures exceeded its principal amount by $473.2 million.

In June 2015, we issued $263.9 million in aggregate principal amount of 1.5% Senior Convertible Debentures due in 2035 in exchange for $256.2 million in aggregate principal amount of our 2.75% 2031 Debentures. Total proceeds, net of issuance costs, were $253.2 million. The 1.5% 2035 Debentures were issued at 97.09% of the principal amount, which resulted in a discount of $7.7 million. The 1.5% 2035 Debentures bore interest at 1.5% per year, payable in cash semi-annually in arrears. In addition to ordinary interest and default additional interest, beginning with the semi-annual interest period commencing on November 1, 2021, contingent interest accrued during any regular semi-annual interest period where the average trading price of our 1.5% 2035 Debentures for the ten trading day period immediately preceding the first day of such semi-annual period was greater than or equal to $1,200 per $1,000 principal amount of our 1.5% 2035 Debentures, in which case, contingent interest accrued at a rate of 0.50% per annum of such average trading price.

During the third quarter of fiscal year 2021, we induced the exchange of $64.9 million notional amount of 1.5% 2035 Debentures for $0.5 million in cash and 3.2 million shares of common stock, of which we allocated $64.2 million to debt and $102.5 million to equity. Also, in connection with the redemptions, we wrote off $1.4 million of unamortized discount. As a result, we recorded a $1.1 million loss associated with the redemptions, of which $0.4 million represents the inducement expense and $0.1 million represents the interest earned at the time of settlement, based upon the guidance in ASC 470-20. Additionally, as part of these redemptions we transferred non-cash consideration in the form of shares of common stock valued at $166.7 million.

The 1.5% 2035 Debentures were convertible during the period October 1, 2021 through November 4, 2021, as our common stock price exceeded the conversion threshold price of 130% of the applicable conversion price per share for at least 20 trading days during the 30 consecutive trading days ending September 30, 2021. The holders previously had the right to convert all or any portion of their debentures at the aforementioned conversion ratio beginning October 1, 2020 through November 4, 2021.

Further, during the third and fourth quarter of fiscal year 2021, holders of our 1.5% 2035 Debentures exercised their right to convert $137.4 million notional amount for $137.4 million in cash and 4.1 million shares of common stock, of which we allocated $136.0 million to debt and $225.1 million to equity. Also, in connection with the conversions, we wrote off $2.4 million of unamortized discount and $0.1 million of unamortized costs. As a result, we recorded a $1.1 million loss associated with the conversions. Additionally, as part of these conversions we transferred non-cash consideration in the form of shares of common stock valued at $223.7 million.

On September 29, 2021, we issued a notice calling for redemption all of our outstanding 1.5% 2035 Debentures, pursuant to which the holders had the right to receive cash at a price equal to 100% of the principal amount of the 1.5% 2035 Debentures plus any accrued and unpaid interest, including any additional interest to, but excluding, the repurchase date of November 5th, 2021. In lieu of redemption, holders had the right to convert all or any portion of their debentures at the aforementioned conversion ratio until the close of business on November 4, 2021. Upon the conclusion of the conversion period on November 4, 2021, holders of $25.0 million notional amount exercised their right to convert. Additionally, we redeemed the remaining outstanding $0.1 million 1.5% 2035 Debentures for $0.1 million in cash. On November 5, 2021, we settled all of the outstanding 1.5% 2035 Debentures for $25.1 million in cash and 0.8 million shares of common stock. As part of these conversions we transferred non-cash consideration in the form of shares of common stock valued at $41.9 million. Following these redemptions and conversions, none of the 1.5% 2035 Debentures remain outstanding.

On July 31, 2020, we amended our revolving credit agreement (the "Amended Revolving Credit Agreement") to, among other things, extend the expiration from April 15, 2021 to April 15, 2022. The Amended Revolving Credit Agreement provided for aggregate borrowing commitments of $242.5 million (the "Revolving Credit Facility"), including the revolving facility loans, the swingline loans and issuance of letters of credit. The borrowing outstanding under the Revolving Credit Facility bore interest at either (i) LIBOR plus an applicable margin of 1.50% or 1.75%, or (ii) the alternative base rate plus an applicable margin of 0.50% or 0.75%. The Revolving Credit Facility was secured by substantially all our assets. The Amended Revolving Credit Agreement contained customary affirmative and negative covenants and conditions to borrowing, as well as customary events of default. At any time that there were any outstanding borrowings (excluding up to $25,000,000 of issued and undrawn Letters of Credit) under the Revolving Credit Facility, we were required to maintain a Consolidated Senior Secured Leverage Ratio (as defined in the Amended Revolving Credit Agreement) not exceeding 4.00 to 1.00.

On February 4, 2021, we entered into a new revolving credit agreement (the "New Revolving Credit Agreement"), which replaced the existing Amended Revolving Credit Agreement. The New Revolving Credit Agreement expires February 4, 2026, and has an aggregate borrowing commitment of $300.0 million, including revolving loans and letters of credit (the "New Revolving Credit Facility"). The New Revolving Credit Facility bears interest at either (i) LIBOR plus an applicable margin of 1.50% or 1.75%, or (ii) the alternative base rate plus an applicable margin of 0.50% or 0.75%. The New Revolving Credit Facility is secured by substantially all our assets and substantially all assets of certain of our domestic subsidiaries that guarantee our obligations under the New Revolving Credit Agreement. The New Revolving Credit Agreement contains customary affirmative and negative covenants and conditions to borrowing, as well as customary events of default. Among other things, we are required to maintain a Consolidated Senior Secured Leverage Ratio (as defined in the New Revolving Credit Agreement) not exceeding 4.00 to 1.00. We were in compliance with all the debt covenants as of December 31, 2021.