Note 4 - Securities Available for Sale - Available-for-sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Due within 1 year, amortized cost	$ 129,251
Due within 1 year, fair value	129,311
Due after 1 but within 5 years, amortized cost	32,124
Due after 1 but within 5 years, fair value	32,208
Due after 5 but within 10 years, amortized cost	6,162
Due after 5 but within 10 years, fair value	6,219
Due after 10 years, amortized cost	108,202
Due after 10 years, fair value	109,139
Mortgage-backed securities – government agencies, amortized cost	193,574
Mortgage-backed securities – government agencies, fair value	193,861
Total securities available-for-sale, amortized cost	469,313	$ 443,742
Total securities available-for-sale, fair value	$ 470,738	$ 436,995

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27198-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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