SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (c) (e) (Details) - USD ($)	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Allowance for doubtful accounts
Movement in valuation and qualifying accounts and reserves
Balance at Beginning of Period	$ 220,000	$ 220,000
Additions Charged to Costs and Expenses	134,000	280,000
Deductions - Describe	114,000	280,000
Balance at End of Period	240,000	220,000
Inventory valuation reserve
Movement in valuation and qualifying accounts and reserves
Balance at Beginning of Period	312,000	435,000
Additions Charged to Costs and Expenses	282,000	78,000
Deductions - Describe	76,000	201,000
Balance at End of Period	518,000	312,000
Reserve for self-insured losses
Movement in valuation and qualifying accounts and reserves
Balance at Beginning of Period	1,861,000	2,334,000
Additions Charged to Costs and Expenses	5,034,000	4,143,000
Deductions - Describe	5,014,000	4,616,000
Balance at End of Period	$ 1,881,000	$ 1,861,000