Note 5 - Loans - Troubled Debt Restructurings That are Performing According to Their Restructured Terms (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016	Dec. 31, 2016 USD ($)
Financing Receivable, Modifications, Number of Contracts	0	0
Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	33		33
Recorded investment	$ 17,264		$ 17,435
Multi-Family Residential [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	9		9
Recorded investment	$ 2,557		$ 2,572
Commercial Real Estate Loans [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	2		2
Recorded investment	$ 2,049		$ 2,062
One-To-Four Family - Mixed Used Property [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	5		5
Recorded investment	$ 1,791		$ 1,800
One-To-Four Family - Residential [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	3		3
Recorded investment	$ 586		$ 591
Taxi Medallion Portfolio Segment [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	12		12
Recorded investment	$ 9,660		$ 9,735
Commercial Business and Other [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	2		2
Recorded investment	$ 621		$ 675