Note 4 - Securities (Details) - Fair Market Value of Securities Segregated by Purpose $ in Thousands	Mar. 31, 2016 USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	$ 47,835
Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	28,809
Federal Home Loan Bank Borrowings [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	19,026
Securities Pledged as Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	18,286
Securities Pledged as Collateral [Member] | Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	18,286
Securities Available to be Pledged [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	29,549
Securities Available to be Pledged [Member] | Public Funds Collateral [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	10,523
Securities Available to be Pledged [Member] | Federal Home Loan Bank Borrowings [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged securities	$ 19,026