Note 3 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-lived, Gross Carrying Amount	$ 12,580	$ 12,580
Finite-lived, Accumulated Amortization	5,011	4,379
Net Carrying Amount	7,569	8,201
Indefinite-lived intangible assets:
Intangible Assets, Gross Carrying Amount	19,290	19,290
Finite-lived, Accumulated Amortization	5,011	4,379
Net Carrying Amount	14,279	14,911
Finite-lived, Gross Carrying Amount	12,580	12,580
Net Carrying Amount	7,569	8,201
Trademarks [Member]
Indefinite-lived intangible assets:
Indefinite-lived, Gross Carrying Amount	6,710	6,710
Net Carrying Amount	6,710	6,710
Customer Relationships [Member]
Finite-lived, Gross Carrying Amount	10,480	10,480
Finite-lived, Accumulated Amortization	3,258	2,717
Net Carrying Amount	7,222	7,763
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	3,258	2,717
Finite-lived, Gross Carrying Amount	10,480	10,480
Net Carrying Amount	7,222	7,763
Patented Technology [Member]
Finite-lived, Gross Carrying Amount	600	600
Finite-lived, Accumulated Amortization	321	250
Net Carrying Amount	279	350
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	321	250
Finite-lived, Gross Carrying Amount	600	600
Net Carrying Amount	279	350
Patents [Member]
Finite-lived, Gross Carrying Amount	590	590
Finite-lived, Accumulated Amortization	522	502
Net Carrying Amount	68	88
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	522	502
Finite-lived, Gross Carrying Amount	590	590
Net Carrying Amount	68	88
Computer Software, Intangible Asset [Member]
Finite-lived, Gross Carrying Amount	270	270
Finite-lived, Accumulated Amortization	270	270
Net Carrying Amount
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	270	270
Finite-lived, Gross Carrying Amount	270	270
Net Carrying Amount
Trade Names [Member]
Finite-lived, Gross Carrying Amount	140	140
Finite-lived, Accumulated Amortization	140	140
Net Carrying Amount
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	140	140
Finite-lived, Gross Carrying Amount	140	140
Net Carrying Amount
Order or Production Backlog [Member]
Finite-lived, Gross Carrying Amount	500	500
Finite-lived, Accumulated Amortization	500	500
Net Carrying Amount
Indefinite-lived intangible assets:
Finite-lived, Accumulated Amortization	500	500
Finite-lived, Gross Carrying Amount	500	500
Net Carrying Amount