DEBT (Tables)

12 Months Ended

Dec. 31, 2015

Senior Notes

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		143,750
	$	575,000

Summary of the liability component of the Notes

        The following is a summary of the carrying value of the Senior Notes as of December 31, 2015 (in thousands):

	December 31, 2015
Principal amount of the Senior Notes	$	575,000
Unamortized debt discount balance		(11,527	)
	$	563,473

Summary of interest expense for the Notes

        The debt discount and debt issuance costs will be amortized as interest expense through April 2022. The following is a summary of interest expense for 2015 (in thousands):

	December 31, 2015
Contractual interest expense	$	46,874
Amortization of debt discount and debt issuance costs		1,466
Total interest expense	$	48,340

Convertible debt

Summary of the liability component of the Notes

        The following is a summary of the liability component of the Convertible Notes as of December 31, 2015 and 2014 (in thousands):

	December 31,
	2015			2014
Principal amount of the Convertible Notes	$	345,000		$	345,000
Unamortized discount of the liability component		(101,965	)		(115,109	)
	$	243,035		$	229,891

Summary of interest expense for the Notes

        The debt discount and debt issuance costs will be amortized as interest expense through September 2021. The following is a summary of interest expense for, 2015 and 2014 (in thousands):

	December 31,
	2015		2014
Stated coupon interest	$	8,625	$	2,683
Amortization of debt discount and debt issuance costs		14,163		4,200
Total interest expense	$	22,788	$	6,883