Note 9 - Other Operating Income and Expense (Details Textual) - USD ($)		3 Months Ended	9 Months Ended
	Apr. 03, 2017	Jul. 01, 2017	Dec. 30, 2017	Dec. 31, 2016
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property			$ 1,590,000	$ 149,000
Business Combination, Bargain Purchase, Gain Recognized, Amount			1,078,000
Truitt Bros. Inc. [Member]
Business Combination, Bargain Purchase, Gain Recognized, Amount	$ 1,078,000	$ 1,096,000	1,078,000
Closed Plant in the Midwest [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			$ 1,081,000