Note 6 - Discontinued Operations - Summary of Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 24, 2016	Sep. 30, 2017	Sep. 24, 2016
Loss, net of tax		$ 51	$ (278)	$ (4)
Broadcast Microwave Services, Inc. (“BMS”) [Member]
Net sales
Operating loss before income taxes
Gain (loss) from disposal of segment		51	(278)	(4)
Loss before taxes		51	(278)	(4)
Income tax provision
Loss, net of tax		$ 51	$ (278)	$ (4)

Amount before tax of gain (loss) not previously recognized resulting from the disposal of a discontinued operation.

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