Note 17 - Disclosure of Financial Instruments Not Reported at Fair Value - Financial Assets and Financial Liabilities That Are Not Measured and Reported at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial assets
Cash and short-term investments	$ 129,078	$ 47,973
Accrued interest receivable	8,162	6,878
Financial liabilities
Accrued interest payable	212	144
Reported Value Measurement [Member]
Financial assets
Cash and short-term investments	129,078	47,973
Mortgage loans held for sale	5,459	3,213
Federal Home Loan Bank stock and other securities	7,666	6,347
Loans, net	2,310,172	2,281,368
Accrued interest receivable	8,162	6,878
Financial liabilities
Deposits	2,481,966	2,520,548
Short-term borrowings	233,824	114,969
FHLB advances	50,110	51,075
Secured borrowings	18,351	15,814
Accrued interest payable	212	144
Estimate of Fair Value Measurement [Member]
Financial assets
Cash and short-term investments	129,078	47,973
Mortgage loans held for sale	6,005	3,481
Federal Home Loan Bank stock and other securities	7,666	6,347
Loans, net	2,302,466	2,284,569
Accrued interest receivable	8,162	6,878
Financial liabilities
Deposits	2,480,641	2,519,725
Short-term borrowings	233,824	114,969
FHLB advances	50,070	50,806
Secured borrowings
Accrued interest payable	212	144
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets
Cash and short-term investments	129,078	47,973
Mortgage loans held for sale
Federal Home Loan Bank stock and other securities
Loans, net
Accrued interest receivable	8,162	6,878
Financial liabilities
Deposits
Short-term borrowings
FHLB advances
Secured borrowings
Accrued interest payable	212	144
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Financial assets
Cash and short-term investments
Mortgage loans held for sale	6,005	3,481
Federal Home Loan Bank stock and other securities	7,666	6,347
Loans, net
Accrued interest receivable
Financial liabilities
Deposits
Short-term borrowings	233,824	114,969
FHLB advances	50,070	50,806
Secured borrowings
Accrued interest payable
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets
Cash and short-term investments
Mortgage loans held for sale
Federal Home Loan Bank stock and other securities
Loans, net	2,302,466	2,284,569
Accrued interest receivable
Financial liabilities
Deposits	2,480,641	2,519,725
Short-term borrowings
FHLB advances
Secured borrowings	18,210	15,731
Accrued interest payable