Note 7 - Stockholders' Equity (Details Textual) - USD ($)	9 Months Ended
Dec. 29, 2018	Mar. 31, 2018	Dec. 30, 2017
Treasury Stock, Shares, Ending Balance	2,578,565
Treasury Stock, Value, Ending Balance	$ 74,896,000	$ 69,556,000	$ 69,941,000
Common Class A [Member]
Treasury Stock, Value, Acquired, Cost Method	160,179
Common Class B [Member]
Treasury Stock, Value, Acquired, Cost Method	$ 9,290

The amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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