Note 4 - Securities (Details) - Fair Market Value of Securities Segregated by Purpose $ in Thousands	Dec. 31, 2015 USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	$ 48,677
Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	29,104
Securities Pledged as Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	20,252
Securities Pledged as Collateral [Member] | Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	17,883
Securities Available to be Pledged [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	28,425
Securities Available to be Pledged [Member] | Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	11,221
Interest Rate Swap [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	4,008
Interest Rate Swap [Member] | Securities Pledged as Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	2,369
Interest Rate Swap [Member] | Securities Available to be Pledged [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	1,639
Federal Home Loan Bank Borrowings [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	15,565
Federal Home Loan Bank Borrowings [Member] | Securities Available to be Pledged [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	$ 15,565