Note 8 - Acquisitions (Details Textual) - USD ($)	3 Months Ended				6 Months Ended
	Mar. 29, 2020	Dec. 29, 2019	Mar. 31, 2019	Dec. 30, 2018	Mar. 29, 2020	Mar. 31, 2019
Revenue from Contract with Customer, Including Assessed Tax	$ 121,367,000		$ 122,704,000		$ 243,710,000	$ 258,905,000
Net Income (Loss) Attributable to Parent, Total	(5,367,000)	$ 5,320,000	(2,678,000)	$ 10,361,000	(46,000)	7,683,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total	(4,990,000)		(2,327,000)		728,000	8,392,000
BHMG [Member]
Revenue from Contract with Customer, Including Assessed Tax	14,648,000
Net Income (Loss) Attributable to Parent, Total	1,013,000
BHMG [Member] | Acquisition-related Costs [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total	$ 10,670,000		$ 962,000		$ 11,866,000	$ 15,614,000