Note 2 - Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Number of Entities Consolidated as Variable Interest Entities	3
Interest Costs Capitalized	$ 11,000	$ 33,000
Goodwill, Impairment Loss	0	0
Research and Development Expense	345,000	496,000
Advertising Expense	$ 119,000	$ 139,000