Note 5 - Loans - Loans Modified and Classified as TDR (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Financing Receivable, Modifications, Number of Contracts	1	4	1	9
Financing Receivable, Modifications, Balance	$ 1,620	$ 1,306	$ 1,620	$ 5,595
Taxi Medallion Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications, Number of Contracts		4		9
Financing Receivable, Modifications, Balance		$ 1,306		$ 5,595
Commercial Business and Other [Member] | Extended Maturity [Member]
Financing Receivable, Modifications, Number of Contracts	1		1
Financing Receivable, Modifications, Balance	$ 1,620		$ 1,620