Note 6 - Fair Value Measurements (Detail) - The Carrying Amounts and Estimated Fair Values of the Company’s Financial Instruments (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 77,726	$ 95,855	$ 88,669	$ 94,309
Held to maturity investment securities	820	820
Loans, net	994,414	980,550
Liabilities
Deposits	1,394,809	1,410,810
Federal funds purchased and other short-term borrowings	25,705	24,083
Securities sold under agreements to repurchase and other long-term borrowings	127,259	129,297
Subordinated notes payable to unconsolidated trusts	48,970	48,970
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Assets
Cash and cash equivalents	77,726	95,855
Held to maturity investment securities	820	820
Loans, net	994,414	980,550
Accrued interest receivable	5,957	6,074
Federal Home Loan Bank and Federal Reserve Bank Stock	9,516	9,516
Liabilities
Deposits	1,394,809	1,410,810
Federal funds purchased and other short-term borrowings	25,705	24,083
Securities sold under agreements to repurchase and other long-term borrowings	127,259	129,297
Subordinated notes payable to unconsolidated trusts	48,970	48,970
Accrued interest payable	1,360	1,370
Estimate of Fair Value, Fair Value Disclosure [Member]
Assets
Cash and cash equivalents	77,726	95,855
Held to maturity investment securities	948	956
Loans, net	994,841	979,301
Accrued interest receivable	5,957	6,074
Liabilities
Deposits	1,397,574	1,414,395
Federal funds purchased and other short-term borrowings	25,705	24,083
Securities sold under agreements to repurchase and other long-term borrowings	144,940	148,680
Subordinated notes payable to unconsolidated trusts	22,068	21,015
Accrued interest payable	1,360	1,370
Fair Value, Inputs, Level 1 [Member]
Assets
Cash and cash equivalents	77,726	95,855
Liabilities
Deposits	874,982	870,145
Fair Value, Inputs, Level 2 [Member]
Assets
Held to maturity investment securities	948	956
Accrued interest receivable	5,957	6,074
Liabilities
Federal funds purchased and other short-term borrowings	25,705	24,083
Securities sold under agreements to repurchase and other long-term borrowings	144,940	148,680
Accrued interest payable	1,360	1,370
Fair Value, Inputs, Level 3 [Member]
Assets
Loans, net	994,841	979,301
Liabilities
Deposits	522,592	544,250
Subordinated notes payable to unconsolidated trusts	$ 22,068	$ 21,015