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Note 17 - Components of Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Balance | $ 178,263 | $ 172,114 | $ 166,303
Unrealized holding gain (loss) on available for sale securities, net of tax | 546 | (800) | (1,064)
Net pension gain (loss) arising during the period, net of tax | 213 | 271 | (1,108)
Less amortization of prior service cost included in net periodic pension cost, net of tax | (71) | (72) | (72)
Reclassification of stranded tax effects from change in tax rate |  |  |
Balance | 184,896 | 178,263 | 172,114
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] |  |  |
Balance | (3,588) | (2,667) | (1,582)
Unrealized holding gain (loss) on available for sale securities, net of tax | 546 | (800) | (1,064)
Reclassification adjustment, net of tax | (6) | (121) | (21)
Net pension gain (loss) arising during the period, net of tax |  |  |
Less amortization of prior service cost included in net periodic pension cost, net of tax |  |  |
Reclassification of stranded tax effects from change in tax rate | (656) |  |
Balance | (3,704) | (3,588) | (2,667)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] |  |  |
Balance | (5,071) | (5,270) | (4,090)
Unrealized holding gain (loss) on available for sale securities, net of tax | 0 |  |
Reclassification adjustment, net of tax |  | 0 | 0
Net pension gain (loss) arising during the period, net of tax | 213 | 271 | (1,108)
Less amortization of prior service cost included in net periodic pension cost, net of tax | (71) | (72) | (72)
Reclassification of stranded tax effects from change in tax rate | (1,062) |  |
Balance | (5,991) | (5,071) | (5,270)
AOCI Attributable to Parent [Member] |  |  |
Balance | (8,659) | (7,937) | (5,672)
Unrealized holding gain (loss) on available for sale securities, net of tax | 546 | (800) | (1,064)
Reclassification adjustment, net of tax | (6) | (121) | (21)
Net pension gain (loss) arising during the period, net of tax | 213 | 271 | (1,108)
Less amortization of prior service cost included in net periodic pension cost, net of tax | (71) | (72) | (72)
Reclassification of stranded tax effects from change in tax rate | (1,718) |  |
Balance | $ (9,695) | $ (8,659) | $ (7,937)

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- Definition Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 + Details
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- Definition Amount, after tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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