Note 5 - Sale of Business Component - Pro Forma Adjustment to Income Statement (Details) - Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] - Maryland-based Facilities Maintenance Business [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Revenue	$ 18,311	$ 22,845
Net income (loss)	$ 358	$ (2,655)
Basic and diluted net income (loss) per share (in dollars per share)	$ 0.02	$ (0.17)