Note 13 - Income Taxes (Details Textual) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 3.5
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	16.1
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	3.4
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	14.9
Increase (Decrease) In Income Tax Penalties and Interest Accrued	0.5	$ 0.1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0.8	0.3
Undistributed Earnings of Foreign Subsidiaries	$ 78.9
Number of Years Exempt from Tax on Income	2 years
Earliest Tax Year [Member]
Open Tax Year	1991
Latest Tax Year [Member]
Open Tax Year	2017
Maximum [Member]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 0.1
Number of Years Subject to Reduced Corporate Tax Rate	8 years
Minimum [Member]
Number of Years Subject to Reduced Corporate Tax Rate	5 years
Domestic Tax Authority [Member]
Operating Loss Carryforwards	$ 45.8
Deferred Tax Assets, Tax Credit Carryforwards, Research		12.0
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	20.8
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	38.3
Deferred Tax Assets, Tax Credit Carryforwards, Research		2.3
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	21.5
Foreign Tax Authority [Member]
Operating Loss Carryforwards	12.1
Israel [Member]
Income Tax Holiday, Aggregate Dollar Amount	$ 2.9	$ 4.1	$ 6.1
Income Tax Holiday, Income Tax Benefits Per Share	$ 0.08	$ 0.11	$ 0.18