Unaudited statements of cash flows (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2020		Feb. 01, 2020	Jan. 31, 2020
Statement of Cash Flows [Abstract]
Lease right-of-use assets	$ 2,406	[1]	$ 2,741	$ 0	[1]

[1] Figures as of July 31, 2020 reflect the Company's February 1, 2020 adoption of Accounting Standards Update ("ASU") No. 2016-02, Leases. For additional details, see Note 3(c), "Summary of significant accounting policies — Impact of recently adopted accounting pronouncements."