Note 11 - Subsequent Events (Details Textual) - Subsequent Event [Member] - KeyBank National Association [Member] $ in Millions	Nov. 02, 2018 USD ($)
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 30
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	2.35%
Revolving Credit Facility [Member] | Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1
Term Loan [Member]
Debt Instrument, Face Amount	$ 10
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	4.75%
Term Loan [Member] | Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	3.75%
Term Loan Base Rate [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Term Loan Base Rate [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	0.50%