Debt (Tables)

9 Months Ended

Sep. 30, 2017

The Company's 1.00% convertible senior notes (the "Notes"), issued in August 2013, consisted of the following components as of September 30, 2017 and December 31, 2016 (in thousands):



	September 30, 2017			December 31, 2016
Equity component, net of equity issue costs	$	60,222		$	60,222
Liability component:
Principal	287,500			287,500
Less: unamortized debt discount	(12,090		)	(22,076		)
Less: unamortized debt issuance costs	(1,065		)	(2,023		)
Net carrying amount	$	274,345		$	263,401

Interest expense related to convertible senior notes

The following table sets forth total interest expense recognized related to the Notes for the three and nine months ended September 30, 2017 and 2016 (in thousands except percentages):



	Three Months Ended September 30,						Nine Months Ended September 30,
	2017			2016			2017			2016
Contractual interest expense	$	718		$	718		$	2,156		$	2,156
Amortization of debt issuance costs	319			320			958			959
Amortization of debt discount	3,379			3,181			9,986			9,405
Total	$	4,416		$	4,219		$	13,100		$	12,520

Effective interest rate	6.5		%	6.5		%	6.5		%	6.5		%