Note 2 - Discontinued Operations (Details Textual)	1 Months Ended		3 Months Ended		6 Months Ended	9 Months Ended
	Jun. 27, 2015 USD ($)	Jun. 28, 2014 USD ($)	Sep. 26, 2015 USD ($)	Sep. 27, 2014 USD ($)	Jun. 28, 2014 USD ($)	Sep. 26, 2015 USD ($)	Sep. 27, 2014 USD ($)
Divestiture-related Costs [Member] | Broadcast Microwave Services, Inc. (“BMS”) and Cohu Electronics [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			$ 0
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			0
Divestiture-related Costs [Member] | Cohu Electronics [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax				$ 0	$ (800,000)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax				$ 0	800,000
Divestiture-related Costs [Member] | Broadcast Microwave Services, Inc. (“BMS”) [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			(1,000,000)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			1,000,000
Contingent Consideration [Member] | Broadcast Microwave Services, Inc. (“BMS”) and Cohu Electronics [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			200,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			$ (200,000)
Broadcast Microwave Services, Inc. (“BMS”) and Cohu Electronics [Member]
Number of Non-core Business Segments Sold						2
Cohu Electronics [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax							$ 4,133,000
Proceeds from Divestiture of Businesses		$ 9,500,000					9,886,000
Disposal Group, Including Discontinued Operation, Contingent Consideration		$ 500,000			$ 500,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax							$ (4,133,000)
Broadcast Microwave Services, Inc. (“BMS”) [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			$ (222,000)			$ (3,232,000)
Disposal Group, Including Discontinued Operation, Consideration	$ 8,000,000
Proceeds from Divestiture of Businesses	5,500,000					5,339,000
Disposal Group, Including Discontinued Operation, Contingent Consideration	$ 2,500,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			222,000			3,232,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			(222,000)	$ (2,598,000)		(5,195,000)	$ (1,171,000)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			$ 222,000	$ 2,598,000		$ 5,195,000	$ 1,171,000