Note 5 - Loans - Troubled Debt Restructurings That Are Performing According to Their Restructured Terms (Details) $ in Thousands		9 Months Ended		12 Months Ended
		Sep. 30, 2019 USD ($)	Sep. 30, 2018	Dec. 31, 2018 USD ($)
Number of contracts		3	1
Performing Financial Instruments [Member]
Number of contracts		25		31
Recorded investment		$ 7,028		$ 8,365
Multi-Family Residential [Member] | Performing Financial Instruments [Member]
Number of contracts		7		7
Recorded investment		$ 1,883		$ 1,916
One-To-Four Family - Mixed Used Property [Member] | Performing Financial Instruments [Member]
Number of contracts		4		5
Recorded investment		$ 1,497		$ 1,692
One-To-Four Family - Residential [Member] | Performing Financial Instruments [Member]
Number of contracts		3		3
Recorded investment		$ 536		$ 552
Taxi Medallion Portfolio Segment [Member] | Performing Financial Instruments [Member]
Number of contracts	[1]	8		15
Recorded investment	[1]	$ 2,161		$ 3,926
Commercial Business and Other [Member] | Performing Financial Instruments [Member]
Number of contracts		3		1
Recorded investment		$ 951		$ 279

[1] Taxi medallion loans in the table above continue to pay as agreed, however the company records interest received on a cash basis.