Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets - Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands		6 Months Ended		12 Months Ended
	Jan. 04, 2017	Jun. 30, 2018	Jun. 24, 2017	Dec. 30, 2017
Mark-to-market adjustments charged to expense		$ 428
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Balance for contingent consideration		2,253
Fair value of contingent consideration at acquisition date	$ 823			823
Mark-to-market adjustments charged to expense		428		1,423
Impact of currency exchange		99		7
Settlement of contingent consideration		(1,500)
Balance for contingent consideration		$ 1,280		$ 2,253