Note 11 - Lease Commitments (Details Textual)	1 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) ft²	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($) ft²
The 315 Lease [Member]
Area of Real Estate Property | ft²	18,000		18,000
Lease Expiration Date	Mar. 31, 2023
The 315 Lease [Member] | Minimum [Member]
Operating Leases, Monthly Rent Expense	$ 34,000
The 315 Lease [Member] | Maximum [Member]
Operating Leases, Monthly Rent Expense	$ 37,000
The 320 Lease [Member]
Area of Real Estate Property | ft²	39,000		39,000
Lessee, Operating Lease, Renewal Term	5 years		5 years
Lease Expiration Date			Mar. 31, 2023
The 320 Lease [Member] | Minimum [Member]
Operating Leases, Monthly Rent Expense			$ 67,000
The 320 Lease [Member] | Maximum [Member]
Operating Leases, Monthly Rent Expense			$ 83,000
The Abingdon Lease [Member]
Lease Expiration Date		Jun. 30, 2033
The Abingdon Lease [Member] | Minimum [Member]
Operating Leases, Monthly Rent Expense		$ 39,000
The Abingdon Lease [Member] | Maximum [Member]
Operating Leases, Monthly Rent Expense		$ 79,000