Note 3 - Loans - Summary of Average Net Investment in Impaired Loans and Interest Income Recognized and Received on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Average recorded investment	$ 1,436	$ 360
Interest income recognized	13
Interest income received	12	2
Commercial Portfolio Segment [Member]
Average recorded investment	6
Interest income recognized
Interest income received
Loans and Finance Receivables [Member] \| Commercial Portfolio Segment [Member]
Average recorded investment	611	41
Interest income recognized	8
Interest income received	8
Mortgage Receivable [Member] \| Residential Portfolio Segment [Member]
Average recorded investment	420	173
Interest income recognized	4
Interest income received	3
Mortgage Receivable [Member] \| Real Estate Construction Loan [Member]
Average recorded investment	399	146
Interest income recognized	1
Interest income received	$ 1	$ 2

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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