Convertible Notes, Net (Tables)

9 Months Ended

Sep. 30, 2019

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Summary of Outstanding Convertible Senior Notes

As of September 30, 2019, 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
May 2017	$	402,500		4.38	%		4.85	%		28.0324		May 5, 2022​​​​​​​
March 2018	$	220,000		4.75	%		5.33	%		27.6052		March 15, 2023

(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 $35.67 and $36.23 per share of class A common stock, respectively, for the May 2017 and March 2018 convertible notes. The cumulative dividend threshold as defined in the respective May 2017 and March 2018 convertible notes supplemental indentures have not been exceeded as of September 30, 2019.

Summary of Details of Net Book Value of Convertible Note

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

	September 30, 2019			December 31, 2018
Face value	$	622,500		$	622,500
Unamortized discount		(9,552	)		(11,740	)
Deferred financing costs		(685	)		(849	)
Net book value	$	612,263		$	609,911

Summary of Details about Interest Expense

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Cash coupon	$	7,015	$	9,277	$	21,045	$	25,333
Discount and issuance cost amortization		792		1,535		2,352		4,242
Total interest expense	$	7,807	$	10,812	$	23,397	$	29,575