Note 5 - Stock-based Compensation - Compensation Expense Associated with Non-vested Stock Grants (Details) - USD ($)	3 Months Ended
	Jul. 02, 2017	Jul. 03, 2016
Allocated share-based compensation	$ 142,000	$ 161,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member]
Allocated share-based compensation	120,000	119,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Employee [Member]
Allocated share-based compensation	56,000	62,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Non Employee Directors [Member]
Allocated share-based compensation	64,000	57,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2015 [Member]
Allocated share-based compensation		28,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2015 [Member] | Employee [Member]
Allocated share-based compensation
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2015 [Member] | Non Employee Directors [Member]
Allocated share-based compensation		28,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2016 [Member]
Allocated share-based compensation	29,000	64,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2016 [Member] | Employee [Member]
Allocated share-based compensation		35,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2016 [Member] | Non Employee Directors [Member]
Allocated share-based compensation	29,000	29,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2017 [Member]
Allocated share-based compensation	62,000	27,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2017 [Member] | Employee [Member]
Allocated share-based compensation	27,000	27,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2017 [Member] | Non Employee Directors [Member]
Allocated share-based compensation	35,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2018 [Member]
Allocated share-based compensation	29,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2018 [Member] | Employee [Member]
Allocated share-based compensation	29,000
Selling, General and Administrative Expenses [Member] | Non-vested Stock Grants [Member] | Fiscal Year 2018 [Member] | Non Employee Directors [Member]
Allocated share-based compensation