Note 1 - Summary of Significant Accounting Policies - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Customer Relationships [Member]
Cost	$ 15,530	$ 12,311
Weighted average life (Year)	8 years 292 days	9 years 146 days
Accumulated amortization	$ (4,782)	$ (4,490)
Net	10,748	7,821
Noncompete Agreements [Member]
Cost	$ 5,551	$ 5,370
Weighted average life (Year)	5 years 36 days	5 years 36 days
Accumulated amortization	$ (4,619)	$ (3,553)
Net	932	1,817
Customer Backlog [Member]
Cost	$ 122	0
Weighted average life (Year)	182 days
Accumulated amortization	$ (10)	0
Net	$ 112	$ 0