Note 7 - Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 01, 2017	Dec. 31, 2016
Balance as of the beginning of the year	$ 59,380	$ 21,679
Acquisitions		37,701
Reduction from working capital proceeds	(1,138)
Balance as of the end of the period	$ 58,242	$ 59,380