Long-term Debt

3 Months Ended

Mar. 31, 2021

Revolving Credit Facility

On June 9, 2017, the Company entered into a Credit Agreement, as amended (the “Credit Agreement”), with Wells Fargo Bank, National Association, as administrative agent and the other lenders parties thereto. The Credit Agreement provides for revolving credit borrowings up to a maximum principal amount of $125.0 million, subject to a commitment increase of $75.0 million. All outstanding amounts owed under the Credit Agreement become due and payable no later than the final maturity date of June 9, 2022. As of March 31, 2021, there was no outstanding balance under the Credit Agreement.

The Credit Agreement also allows for the issuance of letters of credit in the aggregate amount of up to $10.0 million at any one time; outstanding letters of credit reduce the credit available for revolving credit borrowings. As of March 31, 2021, the Company had two outstanding letters of credit for $0.2 million. Substantially all of the Company’s assets are pledged to secure the credit facility.

Borrowings under the Credit Agreement bear interest at the Company’s option of the prime rate (3.25% on March 31, 2021) plus a margin ranging from 0.00% to 0.50% or one month LIBOR (0.11% on March 31, 2021) plus a margin ranging from 1.00% to 1.75%. The Company incurs an annual commitment fee of 0.15% to 0.20% on the unused portion of the line of credit. The additional margin amount and annual commitment fee are dependent on the level of outstanding borrowings. As of March 31, 2021, the Company had $124.8 million of unused borrowing capacity.

The Company is required to comply with various financial covenants under the Credit Agreement. Specifically, the Company is required to maintain a ratio of earnings before interest, taxes, depreciation, and amortization (“EBITDA”) plus stock compensation to interest expense for the previous four consecutive fiscal quarters of not less than 3.00 to 1.00 and a ratio of indebtedness to EBITDA plus stock compensation (“Leverage Ratio”) of not more than 3.00 to 1.00. Additionally, the Credit Agreement currently restricts the payment of dividends that would result in a pro-forma Leverage Ratio of more than 2.00 to 1.00.

At March 31, 2021, the Company was in compliance with all covenants under the Credit Agreement.

Convertible Senior Notes due 2025

On August 14, 2020, the Company issued $230.0 million aggregate principal amount of 1.250% Convertible Senior Notes Due 2025 (the “2025 Notes”) in a private placement to qualified institutional purchasers pursuant to an exemption from registration provided by Section 4(a)(2) and Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The net proceeds from the offerings, after deducting the initial purchasers’ discount and issuance costs of $7.3 million, were $222.7 million. The Company used (i) $172.0 million of the net proceeds to partially repurchase the 2023 Notes (as defined and described below), and (ii) $26.7 million of the net proceeds to fund the cost of entering into the 2025 Notes Hedges

(as defined below), after such cost was partially offset by the proceeds that the Company received from entering into the 2025 Notes Warrants (as defined below). The remaining proceeds of $24.0 million will be used for working capital or other general corporate purposes.

The 2025 Notes bear interest at a rate of 1.250% per year. Interest is payable in cash on February 1 and August 1 of each year, with the first payment made on February 1, 2021. The 2025 Notes mature on August 1, 2025 unless earlier converted, redeemed or repurchased in accordance with their terms prior to such date. The initial conversion rate is 19.3538 shares of the Company’s common stock per $1,000 principal amount of 2025 Notes, which is equivalent to an initial conversion price of approximately $51.67 per share of common stock. After consideration of the 2025 Notes Hedges and 2025 Notes Warrants, the conversion rate is effectively hedged to a price of $81.05 per share of common stock. The conversion rate, and thus the conversion price, may be adjusted under certain circumstances as described in the indenture governing the 2025 Notes (the “2025 Indenture”). The Company may settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election, based on the applicable conversion rate(s). If a “make-whole fundamental change” (as defined in the 2025 Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time. The Company’s intent is to settle the principal amount of the 2025 Notes in cash upon conversion.

Convertible Senior Notes due 2023

On September 11, 2018, the Company issued $143.8 million aggregate principal amount of 2.375% Convertible Senior Notes Due 2023 (the “2023 Notes”) in a private placement to qualified institutional purchasers pursuant to an exemption from registration provided by Section 4(a)(2) and Rule 144A under the Securities Act. The net proceeds from the offerings, after deducting the initial purchasers’ discount and issuance costs of $4.4 million, were $139.4 million.

The 2023 Notes bear interest at a rate of 2.375% per year. Interest is payable in cash on March 15 and September 15 of each year, with the first payment made on March 15, 2019. The 2023 Notes mature on September 15, 2023, unless earlier converted, redeemed or repurchased in accordance with their terms prior to such date. The initial conversion rate is 26.5957 shares of the Company’s common stock per $1,000 principal amount of 2023 Notes, which is equivalent to an initial conversion price of approximately $37.60 per share of common stock. After consideration of the 2023 Notes Hedges (as defined below) and 2023 Notes Warrants (as defined below), the conversion rate is effectively hedged to a price of $46.62 per share of common stock. The conversion rate, and thus the conversion price, may be adjusted under certain circumstances as described in the indenture governing the 2023 Notes (the “2023 Indenture”). The Company may settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election, based on the applicable conversion rate(s). If a “make-whole fundamental change” (as defined in the 2023 Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time. The Company’s intent is to settle the principal amount of the 2023 Notes in cash upon conversion.

In August and December 2020, the Company repurchased a portion of the outstanding 2023 Notes through individual, privately negotiated transactions (the “2023 Notes Partial Repurchase”), leaving 2023 Notes with an aggregate principal amount of $5.1 million outstanding as of March 31, 2021. The Company used $172.0 million of the net proceeds from the 2025 Notes issuance in August 2020 and $9.7 million of additional cash in December 2020 to complete the 2023 Notes Partial Repurchase, of which a total of $127.7 million and $52.7 million were allocated to the liability and equity components of the 2023 Notes, respectively, and $1.3 million was related to the payment of interest. The 2023 Notes Partial Repurchase resulted in a $4.5 million loss on extinguishment during the year ended December 31, 2020, which includes the proportionate amounts of unamortized debt discount and the remaining unamortized debt issuance costs of $2.4 million.

Other Terms of the Notes

The 2025 Notes and 2023 Notes (together, the “Notes”) may be converted at the holder’s option prior to the close of business on the business day immediately preceding August 1, 2025 and September 15, 2023 for the 2025 Notes and 2023 Notes, respectively, but only under the following circumstances:

•during any calendar quarter commencing after the calendar quarter ending on September 30, 2020 and December 31, 2018 for the 2025 Notes and 2023 Notes, respectively, if the last reported sale price per share of the Company’s common stock exceeds 130% of the applicable conversion price for each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter;

•during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) in which the trading price per $1,000 principal amount of

notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the applicable conversion rate on such trading day;

•upon the occurrence of certain corporate events or distributions on the Company’s common stock described in the 2025 Indenture or the 2023 Indenture, as applicable; and

•at any time from, and including, February 3, 2025 and March 15, 2023 for the 2025 Notes and 2023 Notes, respectively, until the close of business on the second scheduled trading day immediately before the applicable maturity date.

The Company may not redeem the Notes at its option before maturity. If a “fundamental change” (as defined in the 2025 Indenture or 2023 Indenture) occurs, then, except as described in the 2025 Indenture or 2023 Indenture, noteholders may require the Company to repurchase their Notes at a cash repurchase price equal to the principal amount of the Notes to be repurchased, plus accrued and unpaid interest, if any.

During the three months ended March 31, 2021, the conditional conversion feature of the 2023 Notes was triggered as the last reported sale price of the Company's common stock was more than or equal to 130% of the conversion price for at least 20 trading days in the period of 30 consecutive trading days ending on March 31, 2021 (the last trading day of the fiscal quarter), and therefore the 2023 Notes are currently convertible, in whole or in part, at the option of the holder during the quarter ending June 30, 2021. Whether the 2023 Notes will be convertible following such period will depend on the continued satisfaction of this condition or another conversion condition in the future. Since the Company has the election of repaying the 2023 Notes in cash, shares of the Company’s common stock, or a combination of both, the Company continued to classify the liability component of the 2023 Notes as long-term debt on the Condensed Consolidated Balance Sheet as of March 31, 2021 (unaudited). As of the date of this filing, none of the holders of the 2023 Notes have submitted requests for conversion. As of March 31, 2021, none of the conditions permitting holders to convert their 2025 Notes had been satisfied and no shares of the Company’s common stock had been issued in connection with any conversions of the 2025 Notes. Based on the closing price of the Company's common stock of $58.72 per share on March 31, 2021, the conversion value of the Notes was greater than the principal amount of the Notes outstanding on a per note basis.

The liability component of the 2025 Notes and 2023 Notes consisted of the following (in thousands):


	March 31, 2021 (unaudited)				December 31, 2020
Liability component:	2025 Notes		2023 Notes		2025 Notes		2023 Notes
Principal	$	230,000	$	5,090	$	230,000	$	5,090
Less: Unamortized debt discount	(43,511)		(389)		(45,690)		(426)
Unamortized debt issuance costs	(4,983)		(72)		(5,271)		(79)
Net carrying amount	$	181,506	$	4,629	$	179,039	$	4,585

Interest expense for the three months ended March 31, 2021 and 2020 related to the 2025 Notes and 2023 Notes consisted of the following (in thousands):

2025 Notes


	Three Months Ended March 31,
	2021		2020
Coupon interest	$	719	$	—
Amortization of debt discount	2,179		—
Amortization of debt issuance costs	287		—
Total interest expense recognized	$	3,185	$	—

2023 Notes


	Three Months Ended March 31,
	2021		2020
Coupon interest	$	30	$	854
Amortization of debt discount	37		977
Amortization of debt issuance costs	7		206
Total interest expense recognized	$	74	$	2,037

Convertible Notes Hedges

In connection with the issuance of the 2025 Notes and 2023 Notes, the Company entered into privately negotiated convertible note hedge transactions (the “2025 Notes Hedges” and the “2023 Notes Hedges,” respectively, and together, the “Notes Hedges”) with certain of the initial purchasers or their respective affiliates and/or other financial institutions (the “Option Counterparties”). The 2025 Notes Hedges provide the Company with the option to acquire, on a net settlement basis, approximately 4.5 million shares of common stock at a strike price of $51.67, which is equal to the number of shares of common stock that notionally underlie the 2025 Notes and correspond to the conversion price of the 2025 Notes. The 2023 Notes Hedges provide the Company with the option to acquire, on a net settlement basis, approximately 0.1 million shares (after consideration of the 2023 Notes Partial Repurchase) of common stock at a strike price of $37.60, which is equal to the number of shares of common stock that notionally underlie the 2023 Notes and correspond to the conversion price of the 2023 Notes after the partial repurchase discussed above. If the Company elects cash settlement and exercises the 2025 Notes Hedges or the 2023 Notes Hedges, the aggregate amount of cash received from the Option Counterparties will cover the aggregate amount of cash that the Company would be required to pay to the holders of the Notes, less the principal amount thereof. The Notes Hedges do not meet the criteria for separate accounting as a derivative as they are indexed to the Company’s stock and are accounted for as freestanding financial instruments. In August and December 2020, in connection with the 2023 Notes Partial Repurchase, the Company terminated 2023 Notes Hedges corresponding to approximately 3.7 million shares for cash proceeds of $50.1 million. The proceeds were recorded as an increase to additional paid-in capital within stockholders' equity.

Convertible Notes Warrants

In connection with the issuance of the 2025 Notes and 2023 Notes, the Company also sold net-share-settled warrants (the “2025 Notes Warrants” and the “2023 Notes Warrants,” respectively, and together, the “Notes Warrants”) in privately negotiated transactions with the Option Counterparties. The strike price of the 2025 Notes Warrants and 2023 Notes Warrants was approximately $81.05 and $46.62 per share, respectively, and is subject to certain adjustments under the terms of their respective Notes Warrants. As a result of the 2025 Notes Warrants and 2023 Notes Warrants and related transactions, the Company is required to recognize incremental dilution of earnings per share to the extent the average share price is over $81.05 for any fiscal quarter for the 2025 Notes Warrants and $46.62 for the 2023 Notes Warrants. The 2025 Notes Warrants and 2023 Notes Warrants expire over a period of 100 trading days commencing on November 1, 2025 and December 15, 2023, respectively, and may be settled in net shares of common stock or net cash at the Company’s election. In August and December 2020, in connection with the 2023 Notes Partial Repurchase, the Company repurchased a portion of the 2023 Notes Warrants through a cash payment of $43.0 million. The repurchase was recorded as a reduction in additional paid-in capital within stockholders' equity.