Convertible Senior Notes (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Schedule of long-term debt instruments

The Notes consisted of the following (in thousands):

	December 31,
	2015			2014
Liability:
Principal	$	1,322,500		$	1,322,500
Less: debt discount and issuance costs, net of amortization (1)	(195,966		)	(240,947		)
Net carrying amount	$	1,126,534		$	1,081,553
Equity	$	230,191		$	230,191

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(1) In the fourth quarter of 2015, the Company adopted new authoritative guidance on presenting debt issuance costs related to a recognized debt liability in the balance sheet as a direct deduction from the carrying amount of that debt liability on a retrospective approach. As a result, the Company reclassified $0.5 million of debt issuance costs to Convertible Senior Notes, net. No adjustments were recorded for prior periods as the impact to the Company's consolidated balance sheet was not material.

Schedule of recognized interest expense

The Company recognized interest expense on the Notes as follows (in thousands, except for percentage):

	Year Ended December 31,
	2015			2014
Contractual interest expense based on 0.50% per annum	$	6,631		$	881
Amortization of debt discount and issuance costs	45,559			5,916
Total	$	52,190		$	6,797
Effective interest rate of the liability component	4.7		%	4.7		%