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Note 2 - Securities - Available-for-sale Securities (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Amortized Cost	$ 339,964,000	$ 336,562,000
Gross Unrealized Gains	1,063,000	927,000
Gross Unrealized Losses	(8,586,000)	(9,429,000)
Fair Value	332,441,000	328,060,000
US Government Agencies Debt Securities [Member]
Amortized Cost	162,923,000	159,271,000
Gross Unrealized Gains	73,000	106,000
Gross Unrealized Losses	(6,985,000)	(7,337,000)
Fair Value	156,011,000	152,040,000
Collateralized Mortgage Backed Securities [Member]
Amortized Cost	43,525,000	47,329,000
Gross Unrealized Gains	472,000	486,000
Gross Unrealized Losses	(293,000)	(423,000)
Fair Value	43,704,000	47,392,000
Municipal General Obligation Bonds [Member]
Amortized Cost	123,235,000	120,284,000
Gross Unrealized Gains	496,000	312,000
Gross Unrealized Losses	(1,201,000)	(1,549,000)
Fair Value	122,530,000	119,047,000
Municipal Revenue Bonds [Member]
Amortized Cost	8,295,000	7,699,000
Gross Unrealized Gains	22,000	23,000
Gross Unrealized Losses	(78,000)	(91,000)
Fair Value	8,239,000	7,631,000
Other Debt and Equity Securities [Member]
Amortized Cost	1,986,000	1,979,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(29,000)	(29,000)
Fair Value	$ 1,957,000	$ 1,950,000

X

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
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- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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