NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	3 Months Ended	12 Months Ended
	Sep. 27, 2014 USD ($)	Jan. 02, 2016 USD ($) item	Jan. 03, 2015 USD ($) item	Dec. 29, 2012	Oct. 03, 2015 USD ($)
RETIREMENT PLANS
Unfunded liabilities related to the Supplemental Profit Sharing Plan		$ 901,000	$ 1,084,000
RESERVE FOR SELF-INSURED AND INSURED LOSSES
Amount of claims and related insured losses		0	156,000
RECLAMATION
Reserve for reclamation activities		5,675,000	5,415,000
Current portion of reserve for reclamation		695,000	2,331,000
Changes in the aggregated product warranty liability
Beginning balance		109,000	104,000
Warranty related expenditures		(150,000)	(250,000)
Warranty expense accrued		162,000	255,000
Ending balance		$ 121,000	$ 109,000
CONCENTRATIONS
Number of customers accounted for 10% or more of total sales | item		0	0
Fiscal year end
Length of fiscal year			364 days	371 days
Pueblo Colorado gravel operations
RECLAMATION
Reserve for reclamation activities					$ 4,000,000
IMPAIRMENT OF LONG-LIVED ASSETS
Write off of unamortized deferred development expenses	$ 1,257,000
Write off of prepaid royalties	$ 401,000