Convertible Senior Notes (Tables)

12 Months Ended

Dec. 31, 2015

Convertible Senior Notes Disclosure [Abstract]

Schedule of long-term debt instruments

The Notes consist of the following (in thousands):

	December 31, 2015			December 31, 2014
Liability component:
Principal	$	300,000		$	300,000
Less: debt discount, net of amortization	(32,382		)	(44,782		)
Net carrying amount	$	267,618		$	255,218
Equity component (1)	$	63,510		63,510

(1) Recorded in the consolidated balance sheets within additional paid-in capital, net of the $1.7 million issuance costs in equity.

Interest expense related to convertible senior notes

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

	Year Ended December 31,
	2015		2014		2013
0.25% coupon	$	750	$	750	$	469,000
Amortization of debt issuance costs	1,247		1,179		705,000
Amortization of debt discount	12,400		11,726		7,002,000
	$	14,397	$	13,655	$	8,176,000