Convertible Senior Notes (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Schedule of Convertible Notes

The Notes consisted of the following (in thousands):

	June 30, 2018			December 31, 2017
Liability component	$	345,000		$	345,000
Debt discount, net of amortization	(16,423		)	(23,178		)
Debt issuance costs, net of amortization	(2,065		)	(2,865		)
Net carrying amount	$	326,512		$	318,957
Equity component	$	63,643		$	63,643
Less: debt issuance costs allocated to equity	(1,582		)	(1,582		)
Net carrying amount	$	62,061		$	62,061

Summary of Interest Expense Recognized Related to Notes

Interest expense recognized on the Notes was as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
0.75% coupon	$	654	$	647	$	1,301	$	1,287
Amortization of debt discount	3,355		3,249		6,755		6,420
Amortization of debt issuance costs	397		354		800		699
Total	$	4,406	$	4,250	$	8,856	$	8,406