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Note 3 - Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Originated Loan [Member]
Number of Contracts	6	6	12	20
Pre- Modification Recorded Principal Balance	$ 5,402,000	$ 1,907,000	$ 7,497,000	$ 5,966,000
Post- Modification Recorded Principal Balance	$ 5,248,000	$ 1,907,000	$ 7,437,000	$ 6,146,000
Acquired Loan [Member]
Number of Contracts	3	6	14	16
Pre- Modification Recorded Principal Balance	$ 195,000	$ 1,551,000	$ 437,000	$ 2,687,000
Post- Modification Recorded Principal Balance	$ 191,000	$ 1,551,000	$ 433,000	$ 2,688,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	6	5	11	13
Pre- Modification Recorded Principal Balance	$ 5,402,000	$ 1,839,000	$ 7,447,000	$ 5,309,000
Post- Modification Recorded Principal Balance	$ 5,248,000	$ 1,839,000	$ 7,387,000	$ 5,488,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	5	3	9	9
Pre- Modification Recorded Principal Balance	$ 3,118,000	$ 1,362,000	$ 4,186,000	$ 4,114,000
Post- Modification Recorded Principal Balance	$ 2,964,000	$ 1,362,000	$ 4,126,000	$ 4,293,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	1	2	2	4
Pre- Modification Recorded Principal Balance	$ 2,284,000	$ 477,000	$ 3,261,000	$ 1,195,000
Post- Modification Recorded Principal Balance	$ 2,284,000	$ 477,000	$ 3,261,000	$ 1,195,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	2	3	2	6
Pre- Modification Recorded Principal Balance	$ 183,000	$ 1,410,000	$ 183,000	$ 2,246,000
Post- Modification Recorded Principal Balance	$ 179,000	$ 1,410,000	$ 179,000	$ 2,245,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	1	1	1	2
Pre- Modification Recorded Principal Balance	$ 33,000	$ 282,000	$ 33,000	$ 399,000
Post- Modification Recorded Principal Balance	$ 29,000	$ 282,000	$ 29,000	$ 399,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0	0	1
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 38,000
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 38,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	1	0	1	0
Pre- Modification Recorded Principal Balance	$ 150,000	$ 0	$ 150,000	$ 0
Post- Modification Recorded Principal Balance	$ 150,000	$ 0	$ 150,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	0	1	0	2
Pre- Modification Recorded Principal Balance	$ 0	$ 64,000	$ 0	$ 745,000
Post- Modification Recorded Principal Balance	$ 0	$ 64,000	$ 0	$ 744,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Number of Contracts	0	1	0	1
Pre- Modification Recorded Principal Balance	$ 0	$ 1,064,000	$ 0	$ 1,064,000
Post- Modification Recorded Principal Balance	$ 0	$ 1,064,000	$ 0	$ 1,064,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	0	1	1	7
Pre- Modification Recorded Principal Balance	$ 0	$ 68,000	$ 50,000	$ 657,000
Post- Modification Recorded Principal Balance	$ 0	$ 68,000	$ 50,000	$ 658,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Number of Contracts	0	1	1	7
Pre- Modification Recorded Principal Balance	$ 0	$ 68,000	$ 50,000	$ 657,000
Post- Modification Recorded Principal Balance	$ 0	$ 68,000	$ 50,000	$ 658,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	1	3	12	10
Pre- Modification Recorded Principal Balance	$ 12,000	$ 141,000	$ 254,000	$ 441,000
Post- Modification Recorded Principal Balance	$ 12,000	$ 141,000	$ 254,000	$ 443,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Number of Contracts	0	2	10	7
Pre- Modification Recorded Principal Balance	$ 0	$ 90,000	$ 217,000	$ 256,000
Post- Modification Recorded Principal Balance	$ 0	$ 90,000	$ 218,000	$ 258,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	1	1	2	3
Pre- Modification Recorded Principal Balance	$ 12,000	$ 51,000	$ 37,000	$ 185,000
Post- Modification Recorded Principal Balance	$ 12,000	$ 51,000	$ 36,000	$ 185,000

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
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