Summary of Significant Accounting Policies - Useful lives of intangible assets (Details)	12 Months Ended
	Jan. 31, 2020
Certifications
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	5 years
Maintenance contracts & related relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	5 years
Existing technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	3 years
Backlog—subscription
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	2 years
Minimum | Customer contracts & related relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	5 years
Minimum | Tradenames / trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	1 year
Maximum | Customer contracts & related relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	9 years
Maximum | Tradenames / trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	2 years