On June 3, 2019 we issued $400.0 million in aggregate principal amount of 2.00% Senior Convertible Notes due 2024 (the "2024 Notes"). The net proceeds from the issuance of the 2024 Notes, after deducting the initial purchasers' transaction fees and offering expenses, were approximately $391.6 million. The 2024 Notes bear interest at a rate of 2.00% per year, payable in cash on June 1 and December 1 of each year, commencing on December 1, 2019, and mature on June 1, 2024, unless earlier converted or repurchased.

The 2024 Notes will be convertible into cash, shares of our common stock or a combination thereof, at our election, at an initial conversion rate of 12.3018 shares of common stock per $1,000 principal amount of 2024 Notes (which is equivalent to an initial conversion price of approximately $81.29 per share), as adjusted pursuant to the terms of the indenture governing the 2024 Notes (the "Indenture"). The conversion rate of the 2024 Notes, and thus the conversion price, may be adjusted in certain circumstances, including in connection with a conversion of the 2024 Notes made following certain fundamental changes and under other circumstances set forth in the Indenture. It is our current intent and policy to settle all conversions of the 2024 Notes through combination settlements of cash and shares of common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2024 Notes and any remaining amounts in shares of common stock.

Prior to 5:00 p.m., New York City time, on the business day immediately preceding March 1, 2024, the 2024 Notes will be convertible only under certain circumstances as set forth in the Indenture, including on any date during any calendar quarter (and only during such calendar quarter) beginning after September 30, 2019 if the closing sale price of the common stock was more than 130% of the applicable conversion price (approximately $105.68 based on the current conversion price of the 2024 Notes) on each applicable trading day for at least 20 trading days (whether or not consecutive) in the period of the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter.

If a fundamental change (as defined in the Indenture) occurs, holders may require the Company to purchase all or a portion of their 2024 Notes for cash at a repurchase price equal to 100% of the principal amount of the 2024 Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The 2024 Notes are our senior unsecured obligations and rank equally in right of payment with any of our current and any future senior unsecured indebtedness, including our 1.50% senior convertible notes due 2020 (the “2020 Notes”) discussed below. The 2024 Notes are effectively subordinated to all of our future secured indebtedness to the extent of the value of the related collateral, and the 2024 Notes are structurally subordinated to indebtedness and other liabilities, including trade payables, of our subsidiaries.

On May 29 and May 31, 2019, in connection with the offering of the 2024 Notes, we entered into convertible note hedge transactions (collectively, the “2024 Note Hedge Transactions”) that cover, subject to customary anti-dilution adjustments, approximately 4.9 million shares of common stock, in the aggregate, at a strike price that initially corresponds to the initial conversion price of the 2024 Notes, subject to adjustment, and are exercisable upon any conversion of the 2024 Notes. The aggregate cost of the 2024 Note Hedge Transactions was $72.0 million.

On May 29 and May 31, 2019, we also entered into privately negotiated warrant transactions (collectively, the “2024 Warrant Transactions” and, together with the 2024 Note Hedge Transactions, the “2024 Call Spread Transactions”), whereby we sold warrants to acquire, subject to customary anti-dilution adjustments, approximately 4.9 million shares of common stock at an initial strike price of approximately $109.43 per share, subject to adjustment. As consideration for the 2024 Warrant Transactions, we received aggregate proceeds of $47.6 million. The net cost of the 2024 Call Spread Transactions was $24.4 million.

The net proceeds from the issuance of the 2024 Notes, after deducting fees and offering expenses, were used for the following: (i) $232.7 million was used to repurchase $221.1 million in aggregate principal amount of the 2020 Notes (as defined below) in privately negotiated transactions concurrently with the offering of the 2024 Notes (ii) $19.6 million was used to repurchase shares of common stock at $62.53 per share, the closing price of the stock on May 29, 2019; and (iii) $24.4

The 2024 Call Spread Transactions were classified as equity. The Company bifurcated the proceeds from the offering of the 2024 Notes between liability and equity components. On the date of issuance, the liability and equity components were calculated to be approximately $328.0 million and $72.0 million, respectively. The initial $328.0 million liability component was determined based on the fair value of similar debt instruments excluding the conversion feature. The initial $72.0 million ($56.9 million net of tax) equity component represents the difference between the fair value of the initial $328.0 million in debt and the $400.0 million gross proceeds. The related initial debt discount of $72.0 million is being amortized over the life of the 2024 Notes using the effective interest method. An effective interest rate of 6.25% was used to calculate the debt discount on the 2024 Notes.

In connection with the above-noted transactions, the Company incurred approximately $8.4 million of directly related costs. The initial purchasers' transaction fees and related offering expenses were allocated to the liability and equity components in proportion to the allocation of proceeds and accounted for as debt and equity issuance costs, respectively. We allocated $6.4 million of debt issuance costs to the liability component, which were capitalized as deferred financing costs. These costs are being amortized as interest expense over the term of the debt using the effective interest method. The remaining $1.9 million of costs ($1.6 million net of tax) allocated to the equity component were recorded as a reduction of the equity component.

On March 11, 2015, we issued $316.0 million in aggregate principal amount of 1.50% Senior Convertible Notes due 2020, referred to as the 2020 Notes. The 2020 Notes bear interest at a rate of 1.50% per year, payable in cash on March 1 and September 1 of each year, which commenced September 1, 2015, and mature on March 1, 2020, unless earlier converted or repurchased. In connection with the initial offering of the 2020 Notes, on March 5 and March 9, 2015, we entered into convertible note hedge transactions (the “2020 Note Hedge Transactions”) that initially covered approximately 4.4 million shares of common stock at a strike price that initially corresponded to the initial conversion price of the 2020 Notes and are exercisable upon any conversion of the 2020 Notes. On March 5 and March 9, 2015, we also entered into warrant transactions (collectively, the "2020 Warrant Transactions" and, together with the 2020 Note Hedge Transactions, the "2020 Call Spread Transactions") to initially acquire, subject to customary anti-dilution adjustments, approximately 4.4 million shares of common stock. The warrants become exercisable and expire in daily tranches over a three and a half month period starting in June 2020. Refer to the 2018 Form 10-K for further details on this transaction.

As noted above, during second quarter 2019, the Company used $232.7 million from the offering of the 2024 Notes to repurchase $221.1 million in aggregate principal amount of the 2020 Notes in privately negotiated transactions concurrently with the offering of the 2024 Notes. As a result of the partial repurchase of the 2020 Notes, $94.9 million in aggregate principal amount of the 2020 Notes remain outstanding as of September 30, 2019. Additionally, on May 29, 2019, in connection with the partial repurchase of the 2020 Notes, the Company entered into partial unwind agreements that amend the terms of the 2020 Note Hedge Transactions to reduce the number of options corresponding to the principal amount of the repurchased 2020 Notes. The unwind agreements also reduce the number of warrants exercisable under the 2020 Warrant Transactions. As a result of the partial unwind transactions, approximately 1.3 million shares of common stock in the aggregate were covered under each of the 2020 Note Hedge Transactions and the 2020 Warrant Transactions as of September 30, 2019. As of September 30, 2019, the warrants under the 2020 Warrant Transactions had a strike price of approximately $86.59 per share, as adjusted. Proceeds received from the unwind of the 2020 Note Hedge Transactions were $9.0 million, and consideration paid for the unwind of the 2020 Warrant Transactions was $4.2 million, resulting in net proceeds received of $4.9 million for the combined unwind transactions which was recorded to equity in second quarter 2019.

We recognized a $5.5 million loss on extinguishment of debt during second quarter 2019 in connection with this repurchase, which was included within "Other Income (Expense), Net" in the condensed consolidated statement of income for the period. The loss on extinguishment represents the difference between the calculated fair value of the debt immediately prior to its derecognition and the carrying amount of the debt component, including any unamortized debt discount and issuance costs. The remaining consideration paid for the partial repurchase of the 2020 Notes was allocated to the reacquisition of the equity component, which equaled $13.0 million ($10.6 million net of tax) and was recorded as a reduction of equity in second quarter 2019. The remaining unamortized debt discount and issuance costs of $3.3 million will continue to be amortized throughout the remaining life of the 2020 Notes, which are set to mature in March 2020.

The remaining 2020 Notes will be convertible into cash, shares of our common stock or a combination thereof, at our election, at a current conversion rate of 14.1153 shares of common stock per $1,000 principal amount of 2020 Notes as of September 30, 2019 (which is equivalent to a conversion price of approximately $70.85 per share), as adjusted pursuant to the

terms of the indenture governing the 2020 Notes (the "2020 Notes Indenture"). The conversion rate of the 2020 Notes, and thus the conversion price, may be adjusted in certain circumstances, including in connection with a conversion of the 2020 Notes made following certain fundamental changes and under other circumstances set forth in the 2020 Notes Indenture. It is our current intent and policy to settle all conversions of the 2020 Notes through combination settlements of cash and shares of common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2020 Notes and any remaining amounts in shares of common stock.

Prior to 5:00 p.m., New York City time, on the business day immediately preceding December 1, 2019, the 2020 Notes will be convertible only under certain circumstances as set forth in the 2020 Notes Indenture, including on any date during any calendar quarter (and only during such calendar quarter) if the closing sale price of our common stock was more than 130% of the applicable conversion price (approximately $92.11 based on the current conversion price of the 2020 Notes) on each applicable trading day for at least 20 trading days in the period of the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter.



	September 30, 2019									December 31, 2018
	2024 Notes			2020 Notes			Total			2020 Notes
Principal	$	400,000		$	94,909		$	494,909		$	316,000
Less:
Unamortized interest discount	(67,857		)	(1,673		)	(69,530		)	(15,428		)
Deferred financing costs	(6,069		)	(174		)	(6,243		)	(1,621		)
Net carrying amount of 2024 and 2020 Notes	$	326,074		$	93,062		$	419,136		$	298,951

The following table presents the amount of interest cost recognized, which is included within "Interest Expense" in our condensed consolidated statements of income, for the three and nine months ended September 30, 2019 and September 30, 2018 relating to the contractual interest coupon, accretion of the debt discount, and the amortization of deferred financing costs (in thousands):



	Three months ended September 30,
	2019						2018
	2024 Notes		2020 Notes		Total		2024 Notes		2020 Notes		Total
Contractual coupon interest	$	2,000	$	356	$	2,356	$	—	$	1,185	$	1,185
Accretion of debt discount	3,088		1,004		4,092		—		3,124		3,124
Amortization of deferred financing costs	276		104		380		—		347		347
Total	$	5,364	$	1,464	$	6,828	$	—	$	4,656	$	4,656



	Nine months ended September 30,
	2019						2018
	2024 Notes		2020 Notes		Total		2024 Notes		2020 Notes		Total
Contractual coupon interest	$	2,600	$	2,468	$	5,068	$	—	$	3,555	$	3,555
Accretion of debt discount	4,189		6,739		10,928		—		9,252		9,252
Amortization of deferred financing costs	374		717		1,091		—		1,042		1,042
Total	$	7,163	$	9,924	$	17,087	$	—	$	13,849	$	13,849