Convertible Senior Notes and Capped Call Transactions | Convertible Senior Notes and Capped Call TransactionsIn September 2019, the Company issued and sold $400.0 million aggregate principal amount of 0.125% Convertible Senior Notes due 2024 (the “Notes”) in a private offering (the “Offering”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The net proceeds from the Offering were $391.2 million, after deducting discounts and commissions and other fees and expenses payable by the Company in connection with the Offering. The Company used $37.1 million of the net proceeds from the Offering to pay the cost of the privately negotiated capped call transactions (the "Capped Call Transactions") it entered into with the initial purchasers of the Notes or their respective affiliates and another financial institution. The Notes were issued pursuant to an indenture (the “Indenture”), by and between the Company and U.S. Bank National Association, as trustee. The Notes are senior unsecured obligations of the Company and will mature on September 15, 2024, unless earlier redeemed, repurchased or converted. The Notes bear interest at a fixed rate of 0.125% per year payable semiannually in arrears on March 15 and September 15 of each year. The Notes will be convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding March 15, 2024, only under the following circumstances: • during any calendar quarter commencing after the calendar quarter ending on December 31, 2019 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock, for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; • during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the Indenture) per $1,000 principal amount of the Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of common stock and the conversion rate for the Notes on each such trading day; • if the Company calls any or all of the Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or • upon the occurrence of specified corporate events as set forth in the Indenture. On or after March 15, 2024 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their Notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances. Upon conversion, the Company may satisfy its conversion obligation by paying and/or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, in the manner and subject to the terms and conditions provided in the Indenture. The Notes are convertible at an initial conversion rate of 35.1849 shares of common stock per $1,000 principal amount of the Notes, which is equivalent to an initial conversion price of $28.42 per share of common stock, subject to adjustment upon the occurrence of specified events. The conversion rate is subject to adjustment under certain circumstances in accordance with the terms of the Indenture. In addition, following certain corporate events that occur prior to the maturity date or if the Company delivers a notice of redemption, the Company will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event or notice of redemption, as the case may be. For example, upon the occurrence of a make-whole fundamental change, as defined in the purchase agreement, the Company will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its Notes in connection with such make-whole fundamental change or during the relevant redemption period. The Company may not redeem the Notes prior to September 20, 2022. The Company may redeem for cash all or any portion of the Notes, at its option, on or after September 20, 2022, if the last reported sale price of common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day preceding the date on which the Company provides notice of redemption at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus any accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the Notes, which means that the Company is not required to redeem or retire the Notes periodically. If the Company undergoes a fundamental change (as defined in the Indenture), holders may require the Company to repurchase for cash all or any portion of their Notes at a fundamental change repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The Indenture includes customary covenants and sets forth certain events of default after which the Notes may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving the Company after which the Notes become automatically due and payable. The Company was in compliance with all applicable covenants as of June 30, 2021. For at least 20 trading days during the period of 30 consecutive trading days ended September 30, 2020, the last reported sale price of the Company’s common stock was equal to or exceeded 130% of the conversion price of the Notes on each applicable trading day. This conversion trigger has been met each quarter since then, including the quarter ended June 30, 2021. As a result, the Notes continue to be convertible at the option of the holders during the fiscal quarter ending September 30, 2021 and remained classified as current liabilities on the unaudited condensed consolidated balance sheet as of June 30, 2021. During the three months ended March 31, 2021, upon the request of certain holders, the Company settled the conversion of the $10.2 million in aggregate principal amount of the Notes (the "2021 Converted Notes") with cash and settled all other amounts owed to the respective holders through the issuance of 181,629 shares of the Company's common stock with an aggregate fair value of approximately $10.1 million. The Company recognized an immaterial amount related to the acceleration of unamortized debt issuance costs related to these early note conversions, which was recorded in interest expense in the accompanying unaudited condensed consolidated statements of operations. As of the date of this filing, no other holders of the Notes have submitted requests for conversion. Transaction costs related to the issuance of the Notes were $8.8 million and are being amortized to interest expense at an effective interest method rate of 0.57% over the term of the Notes. As of June 30, 2021, the Notes have a remaining life of 39 months. The net carrying amount of the liability and equity components of the Notes for the periods presented is as follows: As of June 30, 2021 December 31, 2020 (In thousands) Liability component Principal $ 389,840 $ 400,000 Unamortized discount (1) — (68,270) Unamortized issuance costs (1) (5,523) (5,058) Net carrying amount $ 384,317 $ 326,672 Equity component, net of issuance costs (1) $ — $ 86,764 (1) See Note 1 "Description of Business and Summary of Significant Accounting Policies" for more information regarding the effect of adoption of ASU 2020-06. The interest expense recognized related to the Notes for the periods presented is as follows: Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 (In thousands) Contractual interest expense $ 122 $ 125 $ 240 $ 250 Amortization of debt discount (1) — 4,042 — 8,031 Amortization of debt issuance costs (2) 426 337 1,018 674 Total $ 548 $ 4,504 $ 1,258 $ 8,955 (1) See Note 1 "Description of Business and Summary of Significant Accounting Policies" for more information regarding the effect of adoption of ASU 2020-06. (2) Amortization of debt issuance costs includes the acceleration of unamortized debt issuance costs related to the partial conversion of the Notes. As of June 30, 2021, the total estimated fair value of the Notes was $731.2 million. The fair value was determined based on the closing trading price per $100 of the Notes as of the last day of trading for the period. The fair value of the Notes is primarily affected by the trading price of our common stock and market interest rates. The fair value of the Notes is considered Level 2 within the fair value hierarchy and was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, and quoted prices of the Notes in an over-the-counter market. Capped Call Transactions In September 2019, in connection with the pricing of the Notes and in connection with the initial purchasers’ exercise in full of their option to purchase additional Notes, the Company entered into the Capped Call Transactions. The Capped Call Transactions are generally expected to reduce potential dilution to common stock upon any conversion of the Notes and/or offset any potential cash payments the Company is required to make in excess of the principal amount of converted Notes, as the case may be, with such reduction and/or offset subject to a cap. The Capped Call Transactions have an initial strike price of $28.42 per share, which corresponds to the initial conversion price of the Notes and is subject to certain adjustments, and an initial cap price of $41.34 per share, which is subject to certain adjustments. For accounting purposes, the Capped Call Transactions are separate transactions and not part of the terms of the Notes. As the Capped Call Transactions are considered indexed to our own stock and are considered equity classified, they are recorded in stockholders’ equity and are not accounted for as derivatives. The cost of $37.1 million incurred in connection with the Capped Call Transactions was recorded as a reduction to additional paid in capital. The Capped Call Transactions initially covered, subject to anti-dilution adjustments substantially similar to those applicable to the Notes, 14.1 million shares of our common stock. In connection with the settlement of the 2021 Converted Notes during the three months ended March 31, 2021, the Company terminated a pro rata amount of the Capped Call Transactions pursuant to the terms thereof. As a result of this pro rata termination, the Company received 37,301 shares of its common stock with an aggregate value of approximately $1.9 million based on the trading price of our common stock at that time. As of June 30, 2021, the Capped Call Transactions cover, subject to anti-dilution adjustments, 13.7 million shares of our common stock. |