Note 17 - Federal Funds Purchased and Lines of Credit (Details Textual) $ in Thousands	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Federal Funds Purchased	$ 0	$ 0
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	$ 0	0
Line of Credit Facility Number of Lenders	3
Federal Home Loan Bank Stock	$ 4,537	$ 4,465
Federal Home Loan Bank of San Francisco [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	334,900
Federal Home Loan Bank Stock	4,500
Federal Home Loan Bank of San Francisco [Member] \| Real Estate [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	378,300
Federal Home Loan Bank of San Francisco [Member] \| Equity Securities [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	28,300
Federal Funds Purchased [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 35,000
Federal Funds Purchased [Member] \| Minimum [Member]
Debt Instrument, Interest Rate, Stated Percentage	1.64%
Federal Funds Purchased [Member] \| Maximum [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.29%
Federal Reserve Bank Advances [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 28,500

The number of lenders granting funds under lines of credit.

No definition available.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

+ References

+ Details

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- Definition

Amount of advances from the Federal Home Loan Bank (FHLB).

+ References

+ Details

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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- Definition

Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22 (b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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