| Note 4 - Leases (Details Textual) - USD ($) | 12 Months Ended | ||
|---|---|---|---|
| Mar. 29, 2020 | Apr. 01, 2019 | Mar. 31, 2019 | |
| Operating Lease, Right-of-Use Asset | $ 4,896,000 | $ 1,900,000 | |
| Reclassification from Deferred Rent to Operating Lease, Right-of-Use Asset | 99,000 | ||
| Operating Lease, Liability, Total | 5,150,000 | $ 1,900,000 | |
| Operating Lease, Payments | $ 1,400,000 | ||
| Operating Lease, Weighted Average Remaining Lease Term (Year) | 3 years | ||
| Operating Lease, Weighted Average Discount Rate, Percent | 3.82% | 
| X | ||||||||||
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- Definition The amount of reclassification from deferred rent liability to operating lease right-of-use asset as a result of the application of new accounting standards. No definition available. 
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| X | ||||||||||
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- Definition Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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