Business Combinations - Additional Information (Details)		3 Months Ended		12 Months Ended
	May 07, 2019 USD ($) asset	Jan. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill resulting from deferred tax liabilities		$ 55,000		$ 55,000	$ 44,000
Customer relationships
Business Acquisition [Line Items]
Weighted average useful life				3 years 9 months 18 days
Realm
Business Acquisition [Line Items]
Purchase price pursuant to the merger agreement	$ 39,000,000
Consideration transferred	$ 38,800,000
Number of acquired finite-lived intangible assets | asset	2
Goodwill expected to be tax deductible	$ 0
Goodwill adjustment		$ 400,000	$ 3,500,000
Goodwill resulting from deferred tax liabilities	$ 3,900,000
Acquisition-related costs				$ 600,000
Realm | Developed Technology
Business Acquisition [Line Items]
Weighted average useful life	5 years
Realm | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life	5 years