| Note 9 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Mar. 29, 2020 | Mar. 31, 2019 | 
|---|---|---|
| Employee wage and benefit accruals | $ 428 | $ 441 | 
| Accounts receivable and inventory reserves | 188 | 129 | 
| Deferred rent | 25 | |
| Operating lease liabilities | 1,275 | |
| Intangible assets | 184 | |
| State net operating loss carryforwards | 713 | 710 | 
| Accrued interest and penalty on unrecognized tax liabilities | 43 | 55 | 
| Stock-based compensation | 165 | 148 | 
| Total gross deferred tax assets | 2,812 | 1,692 | 
| Less valuation allowance | (713) | (710) | 
| Deferred tax assets after valuation allowance | 2,099 | 982 | 
| Prepaid expenses | (191) | (175) | 
| Operating lease right of use assets | (1,212) | |
| Intangible assets | (18) | |
| Property, plant and equipment | (239) | (283) | 
| Total deferred tax liabilities | (1,660) | (458) | 
| Net deferred income tax assets | $ 439 | $ 524 | 
| X | ||||||||||
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- Definition Accrued interest and penalty on unrecognized tax liabilities. No definition available. 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from operating lease liabilities. No definition available. 
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- Definition Amount of deferred tax liability attributable to taxable temporary differences. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill. No definition available. 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from employee benefits, classified as other. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred rent. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from leasing arrangements. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of deferred tax consequences attributable to taxable temporary differences derived from prepaid expenses. No definition available. 
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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