Note 3 - Goodwill and Purchased Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 28, 2019	Dec. 29, 2018
Beginning balance		$ 242,127	$ 65,613
Additions			179,263
Impact of currency exchange		(3,877)	(2,749)
Adjustments		1,134
Impairments (1)	[1]	(715)
Ending balance		238,669	242,127
Semiconductor Test and Inspection [Member]
Beginning balance		220,808	65,613
Additions			157,661
Impact of currency exchange		(3,435)	(2,466)
Adjustments		2,117
Impairments (1)	[1]	(715)
Ending balance		218,775	220,808
PCB Test [Member]
Beginning balance		21,319
Additions			21,602
Impact of currency exchange		(442)	(283)
Adjustments		(983)
Impairments (1)	[1]
Ending balance		$ 19,894	$ 21,319

[1] Impairment of goodwill associated with our FSG segment that is presented as discontinued operations. This amount was not pushed down in the consolidated financial statements and was included within the balance of our Semiconductor Test & Inspection segment.