ASSETS ACQUISITIONS - GFP (Details) - USD ($)		3 Months Ended	9 Months Ended
	Jun. 03, 2019	Sep. 28, 2019	Sep. 28, 2019	Jun. 30, 2019	Dec. 29, 2018
Business Acquisition [Line Items]
Goodwill		$ 6,011,000	$ 6,011,000		$ 1,000,000
American Wheatley HVAC And Global Flow Products
Business Acquisition [Line Items]
Purchase price	$ 12,685,000
Estimated working capital adjustment	778,000
Consideration paid in cash	12,163,000
Contingent liability	4,300,000
Accrual For Earn Out Agreement Achievement Of Growth Targets				$ 1,300,000
Trade receivables	1,787,000
Inventory	1,269,000
Property and equipment	2,530,000
Other assets	250,000
Intangibles	4,302,000
Goodwill	3,675,000
Retained liabilities	$ 1,128,000
American Wheatley HVAC And Global Flow Products | Minimum
Business Acquisition [Line Items]
Earn out agreement, achievement of growth targets period	24 months
American Wheatley HVAC And Global Flow Products | Maximum
Business Acquisition [Line Items]
Earn out agreement, achievement of growth targets period	36 months
Selling and administrative expense | American Wheatley HVAC And Global Flow Products
Business Acquisition [Line Items]
Transaction costs		$ 66,000	$ 1,177,000