Note 2 - Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Net carrying amount	$ 1,585	$ 1,900
Gross carrying amount	11,485	11,485
Accumulated amortization	(8,838)	(8,523)
Accumulated impairment losses	(1,062)	(1,062)
Developed Technology Rights [Member]
Net carrying amount	1,474	1,779
Gross carrying amount	6,100	6,100
Accumulated amortization	(4,626)	(4,321)
Accumulated impairment losses
Noncompete Agreements [Member]
Net carrying amount
Gross carrying amount	1,310	1,310
Accumulated amortization	(1,310)	(1,310)
Accumulated impairment losses
Order or Production Backlog [Member]
Net carrying amount
Gross carrying amount	1,300	1,300
Accumulated amortization	(1,300)	(1,300)
Accumulated impairment losses
Trademarks [Member]
Net carrying amount
Gross carrying amount	1,200	1,200
Accumulated amortization	(180)	(180)
Accumulated impairment losses	(1,020)	(1,020)
Customer Relationships [Member]
Net carrying amount
Gross carrying amount	990	990
Accumulated amortization	(990)	(990)
Accumulated impairment losses
Patents [Member]
Net carrying amount	111	121
Gross carrying amount	585	585
Accumulated amortization	(432)	(422)
Accumulated impairment losses	$ (42)	$ (42)