Supplemental financial statement information (Other income (expense), net) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest income	$ 174	$ 2,046	$ 850	$ 5,273
Gain on equity securities	0	285	0	27,570
Acquisition costs	(13)	(32,932)	(79)	(40,712)
Other expense	(582)	(348)	(2,780)	(478)
Total other expense, net	$ (421)	$ (30,949)	$ (2,009)	$ (8,347)

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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The aggregate amount of income from investments (for example, dividends) not considered a component of the entity's core operations.

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Amount of expense related to nonoperating activities, classified as other.

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