Cash Equivalents and Marketable Securities - Narrative (Details)	12 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Minimum
Cash and Cash Equivalents [Line Items]
Marketable securities term	1 year	1 year
Maximum
Cash and Cash Equivalents [Line Items]
Marketable securities term	3 years	3 years

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration