Note 12 - Fair Value Measurements - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Held to maturity investment securities	$ 3,617	$ 3,597
Reported Value Measurement [Member]
Assets
Loans, net	979,827	961,631
Accrued interest receivable	4,707	5,019
Federal Home Loan Bank and Federal Reserve Bank Stock	13,410	9,840
Cash and cash equivalents	98,014	113,534
Held to maturity investment securities	3,461	3,488
Liabilities
Accrued interest payable	279	321
Deposits	1,352,838	1,369,907
Securities sold under agreements to repurchase	32,569	36,370
Federal Home Loan Bank advances	13,562	18,646
Subordinated notes payable to unconsolidated trusts	33,506	33,506
Estimate of Fair Value Measurement [Member]
Assets
Loans, net	973,781	962,437
Accrued interest receivable	4,707	5,019
Federal Home Loan Bank and Federal Reserve Bank Stock	13,410	9,840
Cash and cash equivalents	98,014	113,534
Held to maturity investment securities	3,617	3,597
Liabilities
Accrued interest payable	279	321
Deposits	1,352,783	1,369,567
Securities sold under agreements to repurchase	32,576	36,381
Federal Home Loan Bank advances	13,855	19,114
Subordinated notes payable to unconsolidated trusts	21,110	21,234
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Loans, net	0	0
Accrued interest receivable	0	0
Federal Home Loan Bank and Federal Reserve Bank Stock	0	0
Cash and cash equivalents	98,014	113,534
Held to maturity investment securities	0	0
Liabilities
Accrued interest payable	0	0
Deposits	1,109,354	1,099,211
Securities sold under agreements to repurchase	0	0
Federal Home Loan Bank advances	0	0
Subordinated notes payable to unconsolidated trusts	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Loans, net	0	0
Accrued interest receivable	4,707	5,019
Federal Home Loan Bank and Federal Reserve Bank Stock	0	0
Cash and cash equivalents	0	0
Held to maturity investment securities	3,617	3,597
Liabilities
Accrued interest payable	279	321
Deposits	0	0
Securities sold under agreements to repurchase	32,576	36,381
Federal Home Loan Bank advances	13,855	19,114
Subordinated notes payable to unconsolidated trusts	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Loans, net	973,781	962,437
Accrued interest receivable	0	0
Federal Home Loan Bank and Federal Reserve Bank Stock	13,410	9,840
Cash and cash equivalents	0	0
Held to maturity investment securities	0	0
Liabilities
Accrued interest payable	0	0
Deposits	243,429	270,356
Securities sold under agreements to repurchase	0	0
Federal Home Loan Bank advances	0	0
Subordinated notes payable to unconsolidated trusts	$ 21,110	$ 21,234