INDEBTEDNESS

Revolving Credit Facility

In November 2015, the Company entered into a revolving credit agreement with certain lenders, which extinguished the prior revolving credit agreement and provided for a $375.0 million revolving secured credit facility maturing in November 2020. This revolving credit agreement is secured by certain tangible and intangible assets.

Loans under the credit facility bear interest, at the Company’s option of (i) a base rate based on the highest of the prime rate, the federal funds rate plus 0.50% and an adjusted LIBOR rate for a one-month interest period in each case plus a margin ranging from 0.00% to 1.00%, or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 2.00%. This margin is determined based on the Company’s total leverage ratio for the preceding four fiscal quarters. The Company is obligated to pay other customary fees for a credit facility of this size and type including an annual administrative agent fee of $0.1 million and an unused commitment fee of 0.15%. To date no funds have been drawn under the credit facility, with $375.0 million remaining available. The Company paid $0.6 million in unused commitment fees for both the years ended December 31, 2017 and 2016. As of December 31, 2017, the Company was in compliance with all financial covenants associated with this credit facility.

Convertible Senior Notes

On March 6, 2017, the Company issued an aggregate principal amount of $400.0 million of convertible senior notes (Notes) and an additional 10% or $40.0 million pursuant to the exercise in full of the option to the initial purchasers to cover over-allotments. The Notes mature on March 1, 2022, unless earlier converted or repurchased, and bear interest at a rate of 0.375% payable semi-annually on March 1 and September 1 of each year. The Notes are convertible at an initial conversion rate of 43.5749 shares of the Company's Class A common stock per $1,000 principal amount of Notes, which is equivalent to an initial conversion price of approximately $22.95 per share of Class A common stock. Holders may convert their Notes at any time prior to the close of business on the business day immediately preceding December 1, 2021 only under the following circumstances: (1) during any calendar quarter (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a 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; (2) 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 governing the Notes) 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 of the Company’s Class A common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events, including certain distributions, the occurrence of a fundamental change (as defined in the indenture governing the Notes) or a transaction resulting in the Company’s Class A common stock converting into other securities or property or assets. On or after December 1, 2021, up until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its Notes regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its Class A common stock, or a combination of cash and shares of its Class A common stock, at the Company’s election. It is the Company’s current intent and policy to settle conversions through combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of Notes. The circumstances required to allow the holders to convert their Notes were met as of January 1, 2018. As of February 27, 2018, no holders have converted their Notes.

In accounting for the issuance of the Notes, the Company separated the Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $86.2 million and was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount ("debt discount") is amortized to interest expense over the term of the Notes at an effective interest rate of 5.34% over the contractual terms of the Notes.

Debt issuance costs related to the Notes comprised of discounts and commissions payable to the initial purchasers of $11.0 million and third party offering costs of $0.8 million. The Company allocated the total amount incurred to the liability and equity components of the Notes based on their relative values. Issuance costs attributable to the liability component were $9.4 million and will be amortized to interest expense using the effective interest method over the contractual term. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity.

The Notes consisted of the following (in thousands):



	December 31, 2017
Principal	$	440,000
Less: unamortized debt discount	(73,384		)
Less: unamortized debt issuance costs	(8,044		)
Net carrying amount	$	358,572

The net carrying amount of the equity component of the Notes was as follows (in thousands):



	December 31, 2017
Debt discount related to value of conversion option	$	86,203
Less: allocated debt issuance costs	(2,302		)
Equity component, net	$	83,901

The Company recognized interest expense on the Notes as follows (in thousands, except for percentages):



	Year Ended December 31,
	2017
Contractual interest expense based on 0.375% per annum	1,351
Amortization of debt discount and issuance costs	14,223
Total	15,574
Effective interest rate of the liability component	5.34	%

Convertible Note Hedge and Warrant Transactions

In connection with the offering of the Notes, the Company entered into convertible note hedge transactions with certain financial institutions (Counterparties) whereby the Company has the option to purchase a total of approximately 19.2 million shares of its Class A common stock at a price of approximately $22.95 per share. The total cost of the convertible note hedge transactions was approximately $92.1 million. In addition, the Company sold warrants to the Counterparties whereby the Counterparties have the option to purchase a total of approximately 19.2 million shares of the Company’s Class A common stock at a price of approximately $31.18 per share. The Company received approximately $57.2 million in cash proceeds from the sale of these warrants. Taken together, the purchase of the convertible note hedges and sale of the warrants are intended to reduce dilution from the conversion of the Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted Notes, as the case may be, and to effectively increase the overall conversion price from approximately $22.95 per share to approximately $31.18 per share. As these instruments are considered indexed to the Company's own stock and are considered equity classified, the convertible note hedges and warrants are recorded in stockholders’ equity, are not accounted for as derivatives and are not remeasured each reporting period. The net costs incurred in connection with the convertible note hedge and warrant transactions were recorded as a reduction to additional paid-in capital on the consolidated balance sheets.