Note 13 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets, Valuation Allowance	$ 255,000	$ 452,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	2,400,000	2,300,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	34,800	11,600	$ 17,500
Unrecognized Tax Benefits, Interest on Income Taxes Expense	145,000	$ 110,100	$ 98,500
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 44,600,000
State and Local Jurisdiction [Member] | Earliest Tax Year [Member]
Open Tax Year	2012
State and Local Jurisdiction [Member] | Latest Tax Year [Member]
Open Tax Year	2016
State and Local Jurisdiction [Member] | Deferred Tax Assets Related to Operating Loss Carryforwards [Member]
Deferred Tax Assets, Valuation Allowance	$ 255,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 197,000
Domestic Tax Authority [Member] | Earliest Tax Year [Member]
Open Tax Year	2013
Domestic Tax Authority [Member] | Latest Tax Year [Member]
Open Tax Year	2016