Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands		Oct. 31, 2020		Feb. 01, 2020	Jan. 31, 2020
Leases [Abstract]
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]		us-gaap:PropertyPlantAndEquipmentNet
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:LongTermDebtAndCapitalLeaseObligations
Operating leases:
Lease right-of-use assets		$ 3,192	[1]	$ 2,741	$ 0	[1]
Lease liabilities, current	[1]	1,288			0
Lease liabilities, noncurrent	[1]	2,158			0
Total operating lease liabilities		3,446		$ 2,928
Finance leases:
Property and equipment, at cost		17,078
Accumulated depreciation		(9,555)
Property and equipment, net		7,523
Lease liabilities (included in Current portion of debt and finance leases)		3,018
Lease liabilities, noncurrent (included in Long-term debt and finance leases)		4,589
Total finance lease liabilities		$ 7,607			$ 3,612

[1] Figures as of October 31, 2020 reflect the Company's February 1, 2020 adoption of Accounting Standards Codification No. 842, Leases (ASC 842). For additional details, see Note 3(c), "Summary of significant accounting policies — Impact of recently adopted accounting pronouncements."