9. CONVERTIBLE NOTES, NET

As of September 30, 2017, the following convertible senior notes, or Convertible Notes, were outstanding ($ in thousands):


Convertible Notes Issuance	Face Value		Coupon Rate			All-in Cost⁽¹⁾			Conversion Rate⁽²⁾		Maturity
November 2013	$	172,500		5.25	%		5.87	%		36.1380	December 1, 2018
May 2017		402,500		4.38	%		4.85	%		28.0324	May 5, 2022


(1)		Includes issuance costs that are amortized through interest expense over the life of the Convertible Notes using the effective interest method.
(2)		Represents the shares of class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $27.67 and $35.67 per share of class A common stock, respectively, for the November 2013 and May 2017 convertible notes. As a result of exceeding the cumulative dividend threshold, as defined in the November 2013 convertible notes supplemental indenture, the conversion rate on the November 2013 convertible notes was most recently adjusted on June 28, 2017 from the prior conversion rate of 35.7236 shares of class A common stock per $1,000 principal amount of convertible notes, which was equivalent to a conversion price of $27.99 per share of class A common stock. The cumulative dividend threshold as defined in the May 2017 convertible notes supplemental indenture has not been exceeded as of September 30, 2017.

In May 2017 we issued $287.5 million of convertible notes. In the third quarter of 2017, we issued an additional $115.0 million of convertible notes under the same indenture and with the same terms as the May 2017 convertible notes. Accordingly, as of September 30, 2017, the May 2017 convertible notes had an aggregate outstanding face value of $402.5 million.

The Convertible Notes are convertible at the holders’ option into shares of our class A common stock, only under specific circumstances, prior to the close of business on August 31, 2018 and January 31, 2022, for the November 2013 and May 2017 convertible notes, respectively, at the applicable conversion rate in effect on the conversion date. Thereafter, the Convertible Notes are convertible at the option of the holder at any time until the second scheduled trading day immediately preceding the maturity date. Neither series of the Convertible Notes were convertible as of September 30, 2017. We may not redeem the Convertible Notes prior to maturity. The last reported sale price of our class A common stock of $31.02 on September 29, 2017, the last trading day in the quarter ended September 30, 2017, was greater than the per share conversion price of the November 2013 convertible notes but less than the per share conversion price of the May 2017 convertible notes. We have the intent and ability to settle each series of the Convertible Notes in cash and, as a result, the Convertible Notes did not have any impact on our diluted earnings per share.

Upon our issuance of the November 2013 convertible notes, we recorded a $9.1 million discount based on the implied value of the conversion option and an assumed effective interest rate of 6.50%, as well as $4.1 million of initial issuance costs. Including the amortization of this discount and the issuance costs, our total cost of the November 2013 convertible notes issuance is 7.16% per annum. Upon our issuance of the May 2017 convertible notes, including our additional issuance in the third quarter of 2017, we recorded a $979,000 discount based on the implied value of the conversion option and an assumed effective interest rate of 4.57%, as well as $8.4 million of initial debt discount and issuance costs. Including the amortization of the discount and issuance costs, our total cost of the May 2017 convertible notes issuance is 4.91% per annum.

The following table details our interest expense related to the Convertible Notes ($ in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Cash coupon	$	6,247	$	2,264	$	12,732	$	6,792
Discount and issuance cost amortization		1,202		691		2,869		2,038

Total interest expense	$	7,449	$	2,955	$	15,601	$	8,830

The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands):


	September 30, 2017			December 31, 2016
Face value	$	575,000		$	172,500
Unamortized discount		(11,386	)		(5,532	)
Deferred financing costs		(873	)		(206	)

Net book value	$	562,741		$	166,762

Accrued interest payable for the Convertible Notes was $9.0 million and $755,000 as of September 30, 2017 and December 31, 2016, respectively. Refer to Note 2 for additional discussion of our accounting policies for the Convertible Notes.