Convertible Senior Notes (Tables)

6 Months Ended

Jul. 31, 2020

Debt Disclosure [Abstract]

Convertible Senior Notes

The net carrying amounts of the liability component for each series of Notes as of July 31, 2020 were as follows:

(In thousands)	2023 Notes (1)		2025 Notes		2027 Notes
Liability component:
Principal amount	$	776,661	$	862,500	$	1,265,000
Unamortized discount	(107,910)		(183,507)		(341,190)
Unamortized issuance costs	(4,211)		(5,050)		(13,897)
Net carrying amount	$	664,540	$	673,943	$	909,913

_________________________

⁽¹⁾ Reflects the impact of the 2023 Notes Partial Repurchase on June 5, 2020, as discussed below.

The net carrying amount of the liability component of the 2023 Notes immediately prior to the repurchase was as follows:

	June 5, 2020
(In thousands)	2023 Notes Total		2023 Notes Partial Repurchase
Principal	$	1,265,000	$	488,339
Unamortized debt discount	(184,336)		(71,161)
Unamortized debt issuance costs	(7,194)		(2,777)
Net carrying amount	$	1,073,470	$	414,401

Schedule of Interest Expense

The following tables sets forth the interest expense related to each series of Notes:

	Three Months Ended July 31,				Six Months Ended July 31,
(In thousands)	2020		2019		2020		2019
2023 Notes:
Coupon interest expense	$	1,174	$	1,581	$	2,755	$	3,162
Amortization of debt discount (conversion option)	9,604		12,218		22,022		23,813
Amortization of debt issuance costs	375		477		860		930
Total interest expense related to the 2023 Notes	$	11,153	$	14,276	$	25,637	$	27,905
2025 Notes:
Coupon interest expense	$	2,426	$	2,426	$	4,852	$	4,852
Amortization of debt discount (conversion option)	7,649		7,197		14,961		13,968
Amortization of debt issuance costs	210		198		411		384
Total interest expense related to the 2025 Notes	$	10,285	$	9,821	$	20,224	$	19,204
							Three and Six Months Ended
							July 31, 2020
2027 Notes:
Coupon interest expense							$	2,174
Amortization of debt discount (conversion option)							6,230
Amortization of debt issuance costs							254
Total interest expense related to the 2027 Notes							$	8,658

Calculation of Gain on Extinguishment of Convertible Senior Notes

The 2023 Notes Partial Repurchase resulted in a gain on extinguishment of convertible senior notes, which was calculated as follows:

(In thousands)	2023 Notes Partial Repurchase
Net carrying amount of the liability component associated with the 2023 Notes Partial Repurchase	$	414,401
Less: Cash consideration allocated to the liability component	(407,449)
Gain from the 2023 Notes Partial Repurchase	$	6,952

Other Key Terms and Premiums Paid for Capped Calls

The following table sets forth other key terms and premiums paid for the Capped Calls related to each series of the Notes:

	Capped Calls Entered into in Connection with the Issuance of the 2023 and 2025 Notes		Capped Calls Entered into in Connection with the Issuance of the 2027 Notes
Initial strike price, subject to certain adjustments	$	148.30	$	255.34
Cap price, subject to certain adjustments	$	232.62	$	378.28
Total premium paid (in thousands)	$	274,275	$	137,379