Note 14 - Concentrations of Credit Risk (Details Textual) - Credit Concentration Risk [Member] - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Commercial Real Estate Loans [Member]
Concentration Risk, Percentage	50.00%	51.00%
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure	$ 353,546	$ 340,414
College Housing and Professional Office Buildings [Member]
Concentration Risk, Percentage	26.00%	37.00%
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure	$ 184,203	$ 247,198
Residential [Member]
Concentration Risk, Percentage	25.00%	25.00%
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure	$ 175,456	$ 166,965

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
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-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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