Note 5 - Loans - Troubled Debt Restructurings That Are Not Performing According to Their Restructured Terms (Details) - Nonperforming Financial Instruments [Member] $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Number of contracts, not performing	1	1
Recorded investment, not performing	$ 377	$ 396
Multi-family Residential Portfolio Segment [Member]
Number of contracts, not performing	1	1
Recorded investment, not performing	$ 377	$ 396

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration