Note 8 - Goodwill and Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill	$ 57,831	$ 58,021	$ 57,861
Finite-lived intangible assets, gross	12,259	12,279
Finite-lived intangible assets, accumulated amortization	11,348	10,706
Finite-lived intangible assets, net	911	1,573
Total intangible assets other than goodwill	13,450	13,470
Total intangible assets other than goodwill	2,102	2,764
Customer Relationships [Member]
Finite-lived intangible assets, gross	9,327	9,347
Finite-lived intangible assets, accumulated amortization	9,011	8,611
Finite-lived intangible assets, net	$ 316	$ 736
Customer Relationships [Member] | Minimum [Member]
Finite-lived intangible assets, useful life (Year)	5 years	5 years
Customer Relationships [Member] | Maximum [Member]
Finite-lived intangible assets, useful life (Year)	15 years	15 years
Technology-Based Intangible Assets [Member]
Finite-lived intangible assets, useful life (Year)	7 years	7 years
Finite-lived intangible assets, gross	$ 1,360	$ 1,360
Finite-lived intangible assets, accumulated amortization	765	523
Finite-lived intangible assets, net	595	837
Trade Names [Member]
Finite-lived intangible assets, gross	1,572	1,572
Finite-lived intangible assets, accumulated amortization	1,572	$ 1,572
Finite-lived intangible assets, net
Trade Names [Member] | Minimum [Member]
Finite-lived intangible assets, useful life (Year)	5 years	5 years
Trade Names [Member] | Maximum [Member]
Finite-lived intangible assets, useful life (Year)	10 years	10 years
Trade Names 1 [Member]
Indefinite trade name	$ 1,191	$ 1,191