Note 2 - Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Minimum [Member]
Estimated useful life (Year)	5 years
Minimum [Member] | Computer Equipment and Software [Member]
Estimated useful life (Year)	3 years
Minimum [Member] | Furniture and Fixtures [Member]
Estimated useful life (Year)	5 years
Minimum [Member] | Equipment [Member]
Estimated useful life (Year)	5 years
Maximum [Member]
Estimated useful life (Year)	16 years
Maximum [Member] | Computer Equipment and Software [Member]
Estimated useful life (Year)	5 years
Maximum [Member] | Furniture and Fixtures [Member]
Estimated useful life (Year)	7 years
Maximum [Member] | Equipment [Member]
Estimated useful life (Year)	15 years