Debt

Convertible Notes – Due 2025

In May 2018, the Company issued $1,150.0 million in par value of convertible senior notes due 2025 (the "2025 Notes"). The 2025 Notes are senior unsecured obligations of the Company, bear regular interest of 0.125%, payable semi-annually on May 1 and November 1 of each year, and mature on May 1, 2025, unless repurchased or converted prior to maturity.

At their option, holders may convert their 2025 Notes prior to the close of business on the business day immediately preceding January 1, 2025, only under the following circumstances:

•

during any calendar quarter commencing after the calendar quarter ending on June 30, 2018 (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 the 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 in which the trading price per $1,000 principal amount of 2025 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; or


•	upon the occurrence of specified corporate events.

On or after January 1, 2025, holders may convert all or any portion of their 2025 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances.

Upon conversion, the Company, at its election, may pay or deliver to holders cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock. The initial conversion rate is 10.5150 shares of the Company's common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $95.10 per share, subject to adjustments in certain events, and represents a potential conversion into 12.1 million shares.

In accounting for the issuance of the 2025 Notes, the Company separated the 2025 Notes into liability and equity components. The carrying cost of the liability component was calculated by measuring the fair value of a similar debt obligation that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2025 Notes. The difference between the principal amount of the 2025 Notes and the proceeds allocated to the liability component (“debt discount”) is amortized to interest expense using the effective interest method over the term of the 2025 Notes. The equity component is recorded in additional paid-in capital in the consolidated balance sheet and will not be remeasured as long as it continues to meet the conditions for equity classification.

In accounting for the transaction costs related to the issuance of the 2025 Notes, the Company allocated the total transaction costs incurred to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are being amortized to interest expense over the term of the 2025 Notes, and transaction costs attributable to the equity component are netted against the equity component of the 2025 Notes in stockholders’ equity.

The 2025 Notes consist of the following components as of June 30, 2018 (in thousands):



	June 30, 2018
Liability component:
Principal	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(294,622		)
Net carrying amount	$	855,378

Equity component:	$	285,225

The estimated fair value of the 2025 Notes at June 30, 2018 was $1,157.2 million. The fair value was determined based on the quoted price of the 2025 Notes in an inactive market on the last trading day of the reporting period and has been classified as Level 2 within the fair value hierarchy. Based on the closing price of the Company's common stock of $73.23 on June 30, 2018, the value of the 2025 Notes if converted to common stock was less than the principal amount of $1,150.0 million.

The Company used $46.2 million of the proceeds from the offering to repurchase shares of its common stock, concurrent with the issuance of the 2025 Notes. The repurchase was made in accordance with a share repurchase program previously approved by the Board of Directors. Additionally, $141.8 million of the proceeds was used for the net cost of convertible note hedge and warrant transactions. The remaining net proceeds are intended to be used for the repayment at maturity of the $690.0 million in par value of convertible senior notes due 2019 as well as for working capital, share repurchases, potential acquisitions and strategic transactions and other corporate purposes.

Note Hedge

To minimize the impact of potential dilution upon conversion of the 2025 Notes, the Company entered into convertible note hedge transactions with respect to its common stock in May 2018. The Company paid $261.7 million for the note hedge transactions. The note hedge transactions cover approximately 12.1 million shares of the Company’s common stock at a strike price that corresponds to the initial conversion price of the 2025 Notes, also subject to adjustment, and are exercisable upon conversion of the 2025 Notes. The note hedge transactions are intended to reduce dilution in the event of conversion of the 2025 Notes.

Warrants

Separately, in May 2018, the Company entered into warrant transactions, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, up to 12.1 million shares of the Company’s common stock at a strike price of approximately $149.18 per share. The Company received aggregate proceeds of $119.9 million from the sale of the warrants. The convertible note hedge and warrant transactions will generally have the effect of increasing the conversion price of the 2025 Notes to approximately $149.18 per share.

Convertible Notes – Due 2019

In February 2014, the Company issued $690.0 million in par value of convertible senior notes due 2019 (the "2019 Notes"). The 2019 Notes are senior unsecured obligations of the Company, do not bear regular interest and mature on February 15, 2019, unless repurchased or converted prior to maturity.

At their option, holders may convert their 2019 Notes prior to the close of business on the business day immediately preceding August 15, 2018, only under the following circumstances:

•

during any calendar quarter commencing after the calendar quarter ended June 30, 2014 (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 the period of 30 consecutive trading days ending on 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; or


•	during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of 2019 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; or upon the occurrence of specified corporate events.

On or after August 15, 2018, holders may convert all or any portion of their 2019 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances.

Upon conversion, the Company, at its election, may pay or deliver to holders cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock. The initial conversion rate is 11.1651 shares of the Company's common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $89.56 per share, subject to adjustments in certain events, and represents a potential conversion into 7.7 million shares.

In accounting for the issuance of the 2019 Notes, the Company separated the 2019 Notes into liability and equity components. The carrying cost of the liability component was calculated by measuring the fair value of a similar debt obligation that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2019 Notes. The difference between the principal amount of the 2019 Notes and the proceeds allocated to the liability component (“debt discount”) is amortized to interest expense using the effective interest method over the term of the 2019 Notes. The equity component is recorded in additional paid-in capital in the consolidated balance sheet and will not be remeasured as long as it continues to meet the conditions for equity classification.

In accounting for the transaction costs related to the issuance of the 2019 Notes, the Company allocated the total transaction costs incurred to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are being amortized to interest expense over the term of the 2019 Notes, and transaction costs attributable to the equity component are netted against the equity component of the 2019 Notes in stockholders’ equity.

The 2019 Notes consist of the following components as of June 30, 2018 and December 31, 2017 (in thousands):



	June 30, 2018			December 31, 2017
Liability component:
Principal	$	690,000		$	690,000
Less: debt discount and issuance costs, net of amortization	(15,371		)	(27,087		)
Net carrying amount	$	674,629		$	662,913

Equity component:	$	101,276		$	101,276

The estimated fair value of the 2019 Notes at June 30, 2018 was $692.0 million. The fair value was determined based on the quoted price of the 2019 Notes in an inactive market on the last trading day of the reporting period and has been classified as Level 2 within the fair value hierarchy. Based on the closing price of the Company's common stock of $73.23 on June 30, 2018, the value of the 2019 Notes if converted to common stock was less than the principal amount of $690.0 million.

The Company used $62.0 million of the proceeds from the offering to repurchase shares of its common stock, concurrent with the issuance of the 2019 Notes. The repurchase was made in accordance with a share repurchase program previously approved by the Board of Directors. Additionally, $23.3 million of the proceeds was used for the net cost of convertible note hedge and warrant transactions. The remaining net proceeds are for working capital, share repurchases and other general corporate purposes, as well as for potential acquisitions and strategic transactions.

Note Hedge

To minimize the impact of potential dilution upon conversion of the 2019 Notes, the Company entered into convertible note hedge transactions with respect to its common stock in February 2014. The Company paid $101.3 million for the note hedge transactions. The note hedge transactions cover approximately 7.7 million shares of the Company’s common stock at a strike price that corresponds to the initial conversion price of the 2019 Notes, also subject to adjustment, and are exercisable upon conversion of the 2019 Notes. The note hedge transactions are intended to reduce dilution in the event of conversion of the 2019 Notes.

Warrants

Separately, in February 2014, the Company entered into warrant transactions, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, up to 7.7 million shares of the Company’s common stock at a strike price of approximately $104.49 per share. The Company received aggregate proceeds of $78.0 million from the sale of the warrants. The convertible note hedge and warrant transactions will generally have the effect of increasing the conversion price of the 2019 Notes to approximately $104.49 per share.

Revolving Credit Facility

In May 2018, the Company entered into a $500.0 million five-year, revolving credit agreement (the “Credit Agreement”). Borrowings under the Credit Agreement may be used to finance working capital needs and for general corporate purposes. The Credit Agreement provides for an initial $500.0 million in revolving loans. Under specified circumstances, the facility can be increased to up to $1.0 billion in aggregate principal amount.

Borrowings under the Credit Agreement bear interest, at the Company's option, at a base rate plus a spread of 0.00% to 0.25% or an adjusted LIBOR rate plus a spread of 0.875% to 1.25%, in each case with such spread being determined based on the Company's consolidated leverage ratio specified in the Credit Agreement. Regardless of what amounts, if any, are outstanding under the Credit Agreement, the Company is also obligated to pay an ongoing commitment fee on undrawn amounts at a rate of 0.075% to 0.15%, with such rate being based on the Company's consolidated leverage ratio specified in the Credit Agreement.

The Credit Agreement contains customary representations and warranties, affirmative and negative covenants and events of default. Principal covenants include a maximum consolidated leverage ratio and a minimum consolidated interest coverage ratio. There were no outstanding borrowings under the Credit Agreement as of June 30, 2018.

Interest Expense

The 2025 Notes bear interest at a fixed rate of 0.125%. The interest is payable semi-annually on May 1 and November 1 of each year, commencing in November 2018. The 2025 Notes have an effective interest rate of 4.26% attributable to the conversion feature. The 2019 Notes do not bear regular interest, but have an effective interest rate of 3.2% attributable to the conversion feature. The Company is also obligated to pay ongoing commitment fees under the terms of the Credit Agreement. The following table sets forth total interest expense included in the consolidated statements of income for the three and six months ended June 30, 2018 and 2017 (in thousands):



	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2018			2017			2018			2017
Amortization of debt discount and issuance costs	$	9,917		$	5,681		$	15,749		$	11,313
Coupon interest payable on 2025 Notes	156			—			156			—
Revolving credit facility contractual interest expense	139			—			139			—
Capitalization of interest expense	(1,008		)	(1,035		)	(1,990		)	(2,070		)
Total interest expense	$	9,204		$	4,646		$	14,054		$	9,243