Note 9 - Plant Restructuring (Details Textual) - Closing of East and Northwest Plants [Member] - USD ($)	9 Months Ended
Dec. 29, 2018	Dec. 30, 2017
Restructuring Charges, Total	$ 2,279,000	$ 140,000
Impairment of Long-Lived Assets Held-for-use		$ 17,000
Employee Severance [Member]
Restructuring Charges, Total	1,329,000
Other Restructuring [Member]
Restructuring Charges, Total	$ 950,000

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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