DEBT (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 04, 2015	May 31, 2016	Sep. 28, 2016	Sep. 30, 2015	Sep. 28, 2016	Sep. 30, 2015	Dec. 30, 2015	Mar. 31, 2013
Debt Instrument [Line Items]
Notes payable			$ 0		$ 0		$ 313,000
Interest costs incurred			89,000	$ 83,000	267,000	$ 353,000
Interest costs capitalized					0	$ 108,000
Notes payable
Debt Instrument [Line Items]
Notes payable face amount								$ 313,000
Stated interest rate								5.00%
Notes payable			0		$ 0		313,000
Letter of credit
Debt Instrument [Line Items]
Term to maturity					1 year
Revolving Credit Facility | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 50,000,000
Current borrowing capacity	$ 20,000,000
Term to maturity	5 years
Short-term borrowings			0		$ 0		$ 0
Amount available under revolving credit facility			19,920,000		19,920,000
Revolving Credit Facility | Letter of credit | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 10,000,000
Current borrowing capacity			$ 80,000		$ 80,000
Revolving Credit Facility | Minimum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
Revolving Credit Facility | Minimum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.00%
Revolving Credit Facility | Maximum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		3.25%
Revolving Credit Facility | Maximum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.75%