Convertible Senior Notes (Tables)

12 Months Ended

Jan. 31, 2019

Debt Disclosure [Abstract]

Convertible Debt

The Notes consisted of the following (in thousands):

	As of January 31, 2019
Liability:
Principal	$	575,000
Less: debt discount, net of amortization	(116,722		)
Less: debt issuance costs, net of amortization	(8,450		)
Net carrying amount of the Notes	$	449,828
Stockholders' equity:
Allocated value of the conversion feature	$	136,333
Less: debt issuance costs	(3,068		)
Additional paid-in capital	$	133,265

Interest Expense

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

	Year Ended January 31, 2019
Amortization of debt discount	$	19,611
Amortization of debt issuance costs	1,420
Total amortization of debt discount and debt issuance costs	21,031
Contractual interest expense	584
Total interest expense related to the Notes	$	21,615
Effective interest rate of the liability component	5.6		%