NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 7) (USD $)	12 Months Ended
	Dec. 28, 2013 item	Dec. 29, 2012 item
RETIREMENT PLANS
Unfunded liabilities related to the Supplemental Profit Sharing Plan	$ 1,096,000	$ 872,000
RECLAMATION
Reserve for reclamation activities	1,355,000	1,150,000
Current portion of reserve for reclamation	271,000	230,000
Changes in the aggregated product warranty liability
Beginning balance	127,000	134,000
Warranty related expenditures	(259,000)	(215,000)
Warranty expense accrued	188,000	208,000
Ending balance	56,000	127,000
Number of customers accounted for 10% or more of total sales	0	0
IMPAIRMENT OF LONG-LIVED ASSETS
Impairment charge on other long-lived assets	$ 0
Fiscal year end
Length of fiscal year	364 days	364 days