Note 9 - Other Operating Income and Expense (Details Textual) - USD ($)		3 Months Ended	6 Months Ended
	Apr. 03, 2017	Jul. 01, 2017	Sep. 30, 2017	Oct. 01, 2016
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property			$ 1,591,000	$ (48,000)
Business Combination, Bargain Purchase, Gain Recognized, Amount			1,096,000
Truitt Bros. Inc. [Member]
Business Combination, Bargain Purchase, Gain Recognized, Amount	$ 1,096,000	$ 1,096,000	1,096,000
Closed Plant in the Midwest [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			$ 1,081,000