DEBT (Tables)

3 Months Ended

Mar. 31, 2017

Debt

Schedule of principal amount of the Senior Notes is repayable

The principal amount of the Senior Notes is repayable as follows (amounts in thousands):

April 2, 2018	$	57,500
April 2, 2019		115,000
April 2, 2020		115,000
April 2, 2021		143,750
April 2, 2022		43,750
	$	475,000

Summary of the carrying value of the Senior Notes

The following is a summary of the carrying value of the Senior Notes as of March 31, 2017 and December 31, 2016 (in thousands):

	March 31,		December 31,
	2017		2016
Principal amount of the Senior Notes	$	475,000	$	475,000
Unamortized debt discount balance		(8,025)		(8,605)
Unamortized debt issuance costs		(322)		(344)
	$	466,653	$	466,051

Summary of the liability component of the Convertible Notes

The following is a summary of the liability component of the Convertible Notes as of March 31, 2017 and December 31, 2016 (in thousands):

	March 31,		December 31,
	2017		2016
Principal amount of the Convertible Notes	$	345,000	$	345,000
Unamortized discount of the liability component		(83,775)		(87,570)
Unamortized debt issuance costs		(4,451)		(4,705)
	$	256,774	$	252,725

Senior Notes

Debt

Summary of interest expense for the Notes

The following is a summary of interest expense for the three months ended March 31, 2017 and March 31, 2016 (in thousands):

	Three Months Ended March 31,
	2017		2016
Contractual interest expense	$	12,766	$	15,625
Amortization of debt discount and debt issuance costs		602		518
Total interest expense	$	13,368	$	16,143

Convertible Notes

Debt

Summary of interest expense for the Notes

The following is a summary of interest expense for the three months ended March 31, 2017 and March 31, 2016 (in thousands):

	Three Months Ended March 31,
	2017		2016
Stated coupon interest	$	2,156	$	2,156
Amortization of debt discount and debt issuance costs		4,048		3,718
Total interest expense	$	6,204	$	5,874