Note 3 - Goodwill and Other Purchased Intangible Assets - Changes in Carrying Value of Goodwill by Reportable Segment (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 26, 2015	Dec. 27, 2014
Semiconductor Equipment [Member]
Balance		$ 63,132	$ 67,983
Impact of currency exchange		(2,272)	(4,851)
Balance		60,860	63,132
Balance	[1]	63,132
Balance		$ 60,860	$ 63,132	[1]

[1] Derived from December 27, 2014 audited financial statements