Note 3 - Loans and Allowance for Loan Losses - Troubled Debt Restructurings That are Performing According to Their Restructured Terms (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014
Financing Receivable, Modifications, Number of Contracts	15	1	0
Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	33	24
Recorded investment	$ 17,435	$ 9,509
Multi-Family Residential [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	9	9
Recorded investment	$ 2,572	$ 2,626
Commercial Real Estate Loans [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	2	3
Recorded investment	$ 2,062	$ 2,371
One-To-Four Family - Mixed Used Property [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	5	6
Recorded investment	$ 1,800	$ 2,052
One-To-Four Family - Residential [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	3	1
Recorded investment	$ 591	$ 343
Small Business Administration Portfolio Segment [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	0	1
Recorded investment	$ 0	$ 34
Taxi Medallion Portfolio Segment [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	12	0
Recorded investment	$ 9,735	$ 0
Commercial Business and Other [Member] | Performing Financial Instruments [Member]
Financing Receivable, Modifications, Number of Contracts	2	4
Recorded investment	$ 675	$ 2,083