Note 2 - Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Apr. 14, 2020	Jan. 31, 2020	Jan. 31, 2019	Feb. 01, 2019
Foreign Currency Transaction Gain (Loss), Realized		$ 400	$ (100)
Cash and Cash Equivalents, at Carrying Value, Ending Balance		13,371	10,156
Broker-Dealer, Draft Payable		100	200
Restricted Cash and Cash Equivalents, Total		1,287	2,581
Receivables, Long-term Contracts or Programs, Total		2,300	4,300
Depreciation, Total		4,400	4,500
Impairment of Long-Lived Assets Held-for-use		0
Goodwill, Impairment Loss		0	0
Finite-Lived Patents, Gross		2,700	2,600
Finite-Lived Intangible Assets, Accumulated Amortization		2,500	2,500
Finite-Lived Intangible Assets, Amortization Expense, Year Two		100
Finite-Lived Intangible Assets, Amortization Expense, Year Three		100
Finite-Lived Intangible Assets, Amortization Expense, Year Four		100
Finite-Lived Intangible Assets, Amortization Expense, Year Five		100
Finite-Lived Intangible Assets, Amortization Expense, after Year Five		$ 100
Finite-Lived Intangible Asset, Useful Life (Year)		4 years 109 days
Research and Development Expense, Total		$ 300	200
Operating Lease, Right-of-Use Asset		11,475
Operating Lease, Liability, Total		12,254
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 10,700
Operating Lease, Liability, Total				$ 11,000
Subsequent Event [Member]
Accounts Receivable, Certified Invoices in Process of Collection	$ 500
Accounts Receivable [Member]
Accounts Receivable, before Allowance for Credit Loss		4,100	4,700
Receivables, Long-term Contracts or Programs, Total			$ 3,600
Proceeds from Sale and Collection of Receivables, Total		500
Accounts Receivable, Allowance for Credit Loss, Ending Balance		$ 0
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage		13.30%	42.00%
Accounts Receivable [Member] | Other Noncurrent Assets [Member]
Receivables, Long-term Contracts or Programs, Total		$ 2,100	$ 3,500
Revenue Benchmark [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage		11.50%
Geographic Distribution, Domestic [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance		$ 300	100
Restricted Cash and Cash Equivalents, Total		0	1,500
Geographic Distribution, Foreign [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance		13,100	10,100
Restricted Cash and Cash Equivalents, Total		$ 1,300	$ 1,100