Note 3 - Other Accrued Liabilities (Details Textual) - USD ($)  | 
Jun. 27, 2021  | 
Mar. 28, 2021  | 
|---|---|---|
| Other Accrued Liabilities, Current | $ 341,000 | $ 215,000 | 
| Contract with Customer, Liability, Current | $ 24,000 | $ 85,000 | 
| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Definition Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  |