Note 2 - Discontinued Operations - Summary of Operating Results of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014
Broadcast Microwave Services, Inc. (“BMS”) [Member]
Net sales		$ 2,868	$ 6,965	$ 11,113
Operating loss before income taxes		$ (2,598)	(1,963)	$ (5,062)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	$ (222)		$ (3,232)
Cohu Electronics [Member]
Net sales				$ 5,460
Operating loss before income taxes				(242)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax				4,133
Net sales		$ 2,868	$ 6,965	16,573
Operating loss before income taxes		(2,598)	(1,963)	(5,304)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	$ (222)	(2,598)	(5,195)	$ (1,171)
Income tax provision		(105)	6
Loss, net of tax	$ (222)	$ (2,493)	$ (5,201)	$ (1,171)