Note 3 - Acquisition - Purchase Price (Details) - USD ($) $ in Thousands		12 Months Ended
	May 24, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill		$ 13,738	$ 1,706
Ambrell [Member]
Cash paid to acquire the capital stock of Ambrell	$ 22,610
Estimated fair value of contingent consideration	4,123	4,123
Total purchase price	26,733
Goodwill	12,032	$ 12,032
Identifiable intangible assets	16,300
Cash	648
Trade accounts receivable	3,621
Inventories	1,917
Other current assets	200
Property and equipment	614
Accounts payable	(1,420)
Accrued expenses	(1,280)
Customer advances	(554)
Deferred tax liability	(5,345)
Total purchase price	$ 26,733