Note 7 - Federal Funds Purchased and Lines of Credit (Details Textual)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Federal Funds Purchased	$ 0	$ 0
Line of Credit Facility Number of Lenders	3
Collateralized Agreements	$ 35,000,000
Federal Home Loan Bank of San Francisco [Member] \| Commercial and Real Estate Mortgage Loan Portfolios [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	389,900,000
Federal Home Loan Bank of San Francisco [Member] \| Securities Pledged as Collateral [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	24,200,000
Federal Home Loan Bank of San Francisco [Member] \| Other Assets [Member]
Federal Home Loan Bank Stock	$ 4,500,000
Minimum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	1.39%
Maximum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	2.04%
Federal Home Loan Bank FHLB [Member]
Long-term Line of Credit	$ 0	$ 0
Federal Reserve [Member]
Line of Credit Facility, Maximum Borrowing Capacity	25,200,000
Federal Home Loan Bank of San Francisco Affordable Housing Grant Sponsorships [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 332,400,000

The number of lenders granting funds under lines of credit.

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- Definition

The total of collateralized agreements including securities purchased under agreements to resell (repos), borrowed securities, and secured demand notes.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(2)(i)(A))
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- Definition

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

+ References

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

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 470
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- Definition

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

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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
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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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-Publisher FASB
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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

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