Convertible Senior Notes (Tables)

3 Months Ended

Mar. 31, 2016

Debt Disclosure [Abstract]

Schedule of the Liability and Equity Components of the Convertible Senior Notes

he liability and equity components of the Convertible Senior Notes consisted of the following (in thousands):

	As of March 31, 2016						As of December 31, 2015
	Series A Notes			Series B Notes			Series A Notes			Series B Notes
Liability component:
Principal	$	460,000		$	460,000		$	460,000		$	460,000
Less: Convertible senior notes discounts and issuance costs, net of amortization	(88,726		)	(116,296		)	(93,469		)	(120,333		)
Net carrying amount	$	371,274		$	343,704		$	366,531		$	339,667
Equity component, net of issuance costs	$	92,567		$	117,834		$	92,567		$	117,834

Schedule of Interest Expense related to the Convertible Senior Notes

Interest expense related to the Convertible Senior Notes consisted of the following (in thousands):

	Three Months Ended March 31, 2016
	Series A Notes			Series B Notes
Coupon interest	$	1,150		$	1,869
Amortization of convertible senior notes discounts and issuance costs	4,743			4,037
Total interest expense recognized	$	5,893		$	5,906
Effective interest rate on the liability component	6.4		%	7.0		%