Note 6 - Goodwill and Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill, gross	$ 57,969	$ 57,935
Goodwill, accumulated impairment	(714)	0
Goodwill, Ending Balance	57,255	57,935	$ 57,831
Finite-lived intangible assets, gross	12,276	12,270
Finite-lived intangible assets, accumulated amortization	12,057	11,733
Finite-lived intangible assets, net	219	537
Total intangible assets other than goodwill	13,467	13,461
Total intangible assets other than goodwill	1,410	1,728
Customer Relationships [Member]
Finite-lived intangible assets, gross	9,344	9,338
Finite-lived intangible assets, accumulated amortization	9,256	9,154
Finite-lived intangible assets, net	$ 88	$ 184
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	1,229	1,007
Finite-lived intangible assets, net	131	353
Trade Names [Member]
Finite-lived intangible assets, gross	1,572	1,572
Finite-lived intangible assets, accumulated amortization	$ 1,572	$ 1,572
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