2017 Term Loan B was to mature on February 15, 2023. The 2017 Credit Facility was amended, effective March 16, 2018, to make certain technical amendments in connection with the offering of the 2024 Convertible Notes, as defined below. The Company terminated the 2017 Credit Facility on August 16, 2018 and the $1,178.1 million outstanding was repaid in full. Prior to its termination, the 2017 Term Loan B most recently bore interest at either the eurocurrency rate plus a margin of 5.50% or the base rate plus a margin of 4.50%, and the 2017 Revolving Credit Facility most recently bore interest at either the eurocurrency rate plus a margin of either 4.50% or 4.75% or the base rate plus a margin of either 3.50% or 3.75%, based on the Company’s consolidated leverage ratio. The eurocurrency rate was based on adjusted LIBOR and was subject to a floor of 0.75%. The base rate represented the highest of the Federal Funds Rate plus 0.50%, adjusted LIBOR plus 1.00%, and the prime rate set by Credit Suisse, and was subject to a floor of 1.75%.

Under the 2018 Credit Facility, borrowings under both the 2018 Term Loan A and 2018 Revolving Credit Facility bear interest at either the eurocurrency rate plus a margin of 2.50% or the base rate plus a margin of 1.50%. Borrowings under the 2018 Term Loan B bear interest at either the eurocurrency rate plus a margin of 2.75% or the base rate plus a margin of 1.75%. The eurocurrency rate is based on adjusted LIBOR and is subject to a floor of 0.00%. The base rate represents the highest of the Federal Funds Rate plus 0.50%, adjusted LIBOR plus 1.00%, and the prime rate quoted by The Wall Street Journal, and is subject to a floor of 1.00%. The Company is required to pay a commitment fee on the 2018 Revolving Credit Facility of 0.35% per annum on the undrawn portion of the 2018 Revolving Credit Facility. Interest is due at least quarterly on amounts outstanding under the 2018 Credit Facility.

During the year ended December 31, 2020, the Company recognized $37.2 million of interest expense relating to the 2018 Credit Facility, which included $0.3 million relating to interest expense relating to the debt discount and $1.8 million relating to amortization of debt issuance costs. During the year ended December 31, 2019, the Company recognized $58.9 million of interest expense relating to the 2018 Credit Facility, which included $0.2 million relating to interest expense relating to the debt discount and $1.7 million relating to amortization of debt issuance costs. During the year ended December 31, 2018, the Company recognized $83.6 million of interest expense relating to the 2018 Credit Facility and 2017 Credit Facility, which included $2.9 million relating to interest expense relating to the debt discount and $3.2 million relating to amortization of debt issuance costs.

The fair value of the outstanding borrowings on the 2018 Term Loan A is determined by utilizing market quotes for similar instruments, which are considered Level 2 inputs as described in Note 1, . As of December 31, 2020 and 2019, the carrying value of the 2018 Term Loan A was $250.5 million and $233.2 million, respectively, and the fair value was approximately $251.9 million and $235.7 million, respectively. The fair value of the outstanding borrowings under the 2018 Term Loan B are determined by utilizing market quotes, which are considered Level 2 inputs as described in Note 13, . As of December 31, 2020 and 2019, the carrying amount of the 2018 Term Loan B was $726.0 million and $732.1 million, respectively, and the fair value was approximately $734.0 million and $744.8 million, respectively.

The Company incurred approximately $26.6 million of issuance costs during the first quarter of 2014 relating to the issuance of the 2019 Convertible Notes. Of the $26.6 million issuance costs incurred, $21.5 million and $5.1 million were recorded as debt issuance costs and additional capital, respectively, in proportion to the allocation of the proceeds of the 2019 Convertible Notes. The $21.5 million of debt issuance costs recorded on the Company’s consolidated balance sheet were amortized over the contractual term of the 2019 Convertible Notes using the effective-interest method.

In February 2014, the $1.15 billion aggregate principal amount of the 2019 Convertible Notes were initially allocated between long-term debt, or liability component, and additional capital, or equity component, within the Company’s consolidated balance sheet at $930.9 million and $219.1 million, respectively. The liability component was measured using the nonconvertible debt interest rate. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the face value of the 2019 Convertible Notes as a whole. Since the Company was required to settle these 2019 Convertible Notes at face value at or prior to maturity, this liability component was accreted up to its face value resulting in additional interest expense being recognized within the Company’s consolidated statements of income while the 2019 Convertible Notes remained outstanding. The effective-interest rate on the 2019 Convertible Notes was approximately 6.2% per annum. The equity component was not to be remeasured as long as it continued to meet the conditions for equity classification.

In March 2018, the Company issued $550 million aggregate principal amount of new convertible senior notes due 2024, or 2024 Convertible Notes as described below, and subsequently used the proceeds, along with cash on hand, to repurchase $475.0 million of its existing 2019 Convertible Notes from a limited number of holders in privately negotiated transactions for an aggregate purchase price of $583.5 million, which included $1.0 million of accrued interest. For accounting purposes, pursuant to ASC 470, these transactions were accounted for as an extinguishment of 2019 Convertible Notes and an issuance of new 2024 Convertible Notes. The Company allocated the purchase price between the fair value of the liability component and the equity component of the 2019 Convertible Notes at $459.4 million and $123.0 million, respectively. As a result, the Company recognized $446.4 million as a reduction to long-term debt representing the carrying value of the liability component and $123.0 million as a reduction to additional capital representing the equity component of the repurchased 2019 Convertible Notes. The $13.1 million difference between the fair value and carrying value of the liability component of the repurchased 2019 Convertible Notes was recognized as a loss on extinguishment of debt as a result of the transaction and was recorded in other expense (income), net within the Company’s consolidated statement of income during the year ended December 31, 2018. The accounting impact of the 2024 Convertible Notes is described in further detail below.

During the years ended December 31, 2019 and 2018, the Company recognized $27.0 million and $48.5 million, respectively, of interest expense relating to the 2019 Convertible Notes, which included $17.0 million and $29.8 million, respectively, relating to interest expense relating to the debt discount and $1.7 million and $2.9 million, respectively, relating to amortization of debt issuance costs.

In conjunction with the issuance of the 2019 Convertible Notes, during February 2014, the Company paid approximately $685.8 million to enter into prepaid forward share repurchase transactions, or the Forward Transactions, with certain financial institutions, and paid approximately $123.8 million to enter into capped call transactions with respect to its common shares, or the Capped Call Transactions, with certain financial institutions. Subsequently, in conjunction with the repurchase of a portion of the 2019 Convertible Notes, during March 2018, the Company entered into agreements with the option counterparties to the Capped Call Transactions to terminate a portion of such existing transactions. See Note 8, , for additional discussion on the Forward Transactions and Capped Call Transactions entered into in conjunction with the issuance of these 2019 Convertible Notes.

In March 2018, the Company issued $550 million aggregate principal amount of convertible senior notes, or the 2024 Convertible Notes, in a private offering to qualified institutional buyers, pursuant to Rule 144A under the Securities Act of 1933, as amended. The 2024 Convertible Notes are senior unsecured obligations which rank effectively subordinate to any of the Company’s existing and future secured indebtedness, including amounts outstanding under the 2018 Credit Facility, to the extent of the value of the assets securing such indebtedness. The 2024 Convertible Notes pay interest at a rate of 2.625% per annum payable semiannually in arrears on March 15 and September 15 of each year, beginning on September 15, 2018. Unless redeemed, repurchased or converted in accordance with their terms prior to such date, the 2024 Convertible Notes mature on March 15, 2024. Holders of the 2024 Convertible Notes may convert their notes at their option under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending June 30, 2018, if the last reported sale price of the Company’s common shares for at least 20 trading days (whether or not consecutive) in a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds 130% of the conversion price for the 2024 Convertible Notes on each applicable trading day; (ii) during the five period immediately after any five consecutive trading day period, or the measurement period, in which the trading price per $1,000 principal amount of 2024 Convertible Notes for each trading day of that measurement period was less than 98% of the product of the last reported sale price of the Company’s common shares and the conversion rate for the 2024 Convertible Notes for each such day; (iii) if the Company calls the 2024 Convertible Notes for redemption; or (iv) upon the occurrence of specified corporate events. On and after December 15, 2023, holders may convert their 2024 Convertible Notes at any time, regardless of the foregoing circumstances. Upon conversion, the 2024 Convertible Notes will be settled, at the Company’s election, in cash, the Company’s common shares, or a combination thereof, based on the applicable conversion rate at such time. The 2024 Convertible Notes had an initial conversion rate of 16.0056 common shares per $1,000 principal amount of the 2024 Convertible Notes, or an initial conversion price of approximately $62.48 per common share. The conversion rate is subject to adjustment upon the occurrence of certain events and was 16.0352 common shares per $1,000 principal amount of the 2024 Convertible Notes, or a conversion price of approximately $62.36 per common share, as of December 31, 2020.

The Company incurred approximately $12.9 million of issuance costs during the first quarter of 2018 relating to the issuance of the 2024 Convertible Notes. Of the $12.9 million issuance costs incurred, $9.6 million and $3.3 million were recorded as debt issuance costs and additional capital, respectively, in proportion to the allocation of the proceeds of the 2024 Convertible Notes. The $9.6 million of debt issuance costs, which was recorded as an additional debt discount on the Company’s consolidated balance sheet, are being amortized over the contractual term of the 2024 Convertible Notes using the effective-interest method.

In March 2018, the $550 million aggregate principal amount of the 2024 Convertible Notes were initially allocated between long-term debt, or liability component, and additional or equity component, within the Company’s consolidated balance sheet at $410.1 million and $139.9 million, respectively. The liability component was measured using the nonconvertible debt interest rate. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the face value of the 2024 Convertible Notes as a whole. Since the Company must still settle these 2024 Convertible Notes at face value at or prior to maturity, this liability component will be accreted up to its face value resulting in additional interest expense being recognized within the Company’s consolidated statements of income while the 2024 Convertible Notes remain outstanding. The effective-interest rate on the 2024 Convertible Notes is approximately 8.4% per annum. The equity component is not remeasured as long as it continues to meet the conditions for equity classification.

During the years ended December 31, 2020, 2019, and 2018, the Company recognized $37.7 million, $35.8 million, and $26.6 million, respectively, of interest expense relating to the 2024 Convertible Notes, which included $21.8 million, $20.0 million, and $14.5 million, respectively, relating to interest expense relating to the debt discount and $1.5 million, $1.4 million, and $1.0 million, respectively, relating to amortization of debt issuance costs.

As of December 31, 2020, the outstanding principal on the 2025 Notes was $600.0 million, the unamortized debt issuance costs were $7.1 million, and the carrying amount was $592.9 million, which was recorded to long-term debt within the Company’s consolidated balance sheet. The fair value of the 2025 Notes was approximately $656.3 million as of December 31, 2020 and was determined by utilizing over-the-counter market quotes and yield curves, which are considered Level 2 inputs as defined in Note 1, .

As of December 31, 2020, the outstanding principal on the 2026 Notes was $400.0 million, the unamortized debt issuance costs were $4.1 million, and the carrying amount was $395.9 million, which was recorded to long-term debt within the Company’s consolidated balance sheet. As of December 31, 2019, the outstanding principal on the 2026 Notes was $400.0 million, the unamortized debt issuance costs were $4.7 million, and the carrying amount was $395.3 million, which was recorded to long-term debt within the Company’s consolidated balance sheet. The fair value of the 2026 Notes was approximately $425.0 million and $424.1 million as of December 31, 2020 and 2019, respectively, and was determined by utilizing over-the-counter market quotes and yield curves, which are considered Level 2 inputs as defined in Note 13, .

Certain vendors and government agencies may require letters of credit or similar guaranteeing arrangements to be issued or executed. As of December 31, 2020, the Company had $41.9 million of issued but undrawn letters of credit or similar arrangements, which included the Mexico Value Added Tax, or VAT, related letter of credit described in Note 7, .