DEBT (Tables)

3 Months Ended

Mar. 31, 2020

Debt Disclosure [Abstract]

Schedule of Debt

Total net proceeds from the Notes and Capped Call Transactions:

(in thousands)	Amount
Principal	$	600,000
Less: issuance costs	(14,527)
Less: Capped Call Transactions	(51,900)
	$	533,573

Contractual Obligation, Fiscal Year Maturity Schedule

Net carrying amount of the liability component:

(in thousands)	March 31, 2020
Principal	$	600,000
Unamortized debt discount	(82,624)
Unamortized issuance costs	(12,268)
	$	505,108

Net carrying amount of the equity component, included in additional paid in capital:

(in thousands)	March 31, 2020
Conversion options (1)	$	61,604

(1) Net of issuance costs and taxes.

Interest expense related to the Notes:

	Three Months Ended March 31,
(in thousands)	2020
Contractual interest expense (0.75% coupon)	$	450
Amortization of debt discount (1)	1,497
Amortization of issuance cost (1)	222
	$	2,169

(1) Amortized based upon an effective interest rate of 4.31%.

Future payments of principal and contractual interest:

	March 31, 2020
(in thousands)	Principal		Interest		Total
2020	$	—	$	2,338	$	2,338
2021	—		4,500		4,500
2022	—		4,500		4,500
2023	—		4,500		4,500
2024	—		4,500		4,500
2025	600,000		1,488		601,488
	$	600,000	$	21,826	$	621,826

Schedule of Derivative Instruments

Change in value of Capped Call Transactions:

(in thousands)	Three Months Ended March 31, 2020
Value at issuance	$	51,900
Fair value adjustment	(18,592)
Balance as of March 31,	$	33,308