Convertible Senior Notes and Capped Call Transactions (Tables)

6 Months Ended

Jun. 30, 2020

Debt Disclosure [Abstract]

Schedule of Carrying Amount of Convertible Debt and Related Interest

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

	As of June 30, 2020			As of December 31, 2019
Principal	$	230,000		$	230,000
Unamortized discount	(40,518		)	(45,295		)
Unamortized issuance costs	(5,093		)	(5,693		)
Net carrying amount	$	184,389		$	179,012

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

	As of June 30, 2020
Proceeds allocated to the conversion options (debt discount)	$	52,900
Issuance costs	(1,986		)
Net carrying amount	$	50,914

The following table sets forth the interest expense recognized related to the Notes (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Contractual interest expense	$	431	$	431	$	863	$	575
Amortization of issuance costs	303		260		600		376
Amortization of debt discount	2,409		2,263		4,776		2,990
Total interest expense	$	3,143	$	2,954	$	6,239	$	3,941