Convertible Senior Notes, Net (Tables)

6 Months Ended

Jul. 31, 2019

The Notes, net consisted of the following (in thousands):



	July 31, 2019						January 31, 2019
	2020 Notes			2022 Notes			2020 Notes			2022 Notes
Principal amounts:
Principal	$	249,948		$	1,150,000		$	249,975		$	1,150,000
Unamortized debt discount	(10,987		)	(146,070		)	(16,480		)	(167,249		)
Unamortized debt issuance costs	(644		)	(9,058		)	(981		)	(10,487		)
Net carrying amount	$	238,317		$	994,872		$	232,514		$	972,264
Carrying amount of the equity component ⁽¹⁾	$	66,007		$	219,702		$	66,007		$	219,702

⁽¹⁾

Included on the condensed consolidated balance sheets within Additional paid-in capital, net of $2 million and $4 million for the 2020 Notes and 2022 Notes, respectively, in equity issuance costs.

Schedule of Interest Expense Recognized Related to Convertible Senior Notes

The following table sets forth total interest expense recognized related to the Notes (in thousands):



	Three Months Ended July 31,										Six Months Ended July 31,
	2019				2018						2019				2018
	2020 Notes		2022 Notes		2018 Notes		2020 Notes		2022 Notes		2020 Notes		2022 Notes		2018 Notes		2020 Notes		2022 Notes
Contractual interest expense	$	938	$	719	$	540	$	938	$	719	$	1,875	$	1,438	$	1,196	$	1,875	$	1,438
Interest cost related to amortization of debt issuance costs	168		715		289		169		715		337		1,429		641		337		1,429
Interest cost related to amortization of the debt discount	2,768		10,650		3,567		2,601		10,175		5,493		21,179		7,850		5,162		20,236