Note 7 - Loans and Allowance for Loan Losses (Detail) - Past Due Loans 30 Days Or More By Class Of Loans (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Total Loans	$ 1,040,439	$ 1,072,108
Total Loans	1,040,439	1,072,108
Real Estate Construction And Land Development [Member]
30-89 Days Past Due		3,343
90 Days Or More Past Due	17,365	18,970
Total	17,365	22,313
Current	99,036	97,676
Total Loans	116,401	119,989
Total Loans	116,401	119,989
Real Estate Mortgage Residential [Member]
30-89 Days Past Due	2,526	5,836
90 Days Or More Past Due	7,578	7,352
Total	10,104	13,188
Current	420,547	432,276
Total Loans	430,651	445,464
Total Loans	430,651	445,464
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
30-89 Days Past Due	11,698	1,684
90 Days Or More Past Due	12,955	12,497
Total	24,653	14,181
Current	356,189	370,150
Total Loans	380,842	384,331
Total Loans	380,842	384,331
Commercial And Industrial [Member]
30-89 Days Past Due	212	98
90 Days Or More Past Due	475	300
Total	687	398
Current	47,009	48,373
Total Loans	47,696	48,771
Total Loans	47,696	48,771
States and Political Subdivisions [Member]
Current	22,779	23,601
Total Loans	22,779	23,601
Total Loans	22,779	23,601
Lease Financing [Member]
30-89 Days Past Due	8	80
90 Days Or More Past Due	161	96
Total	169	176
Current	4,298	6,976
Total Loans	4,467	7,152
Total Loans	4,467	7,152
Commercial Other [Member]
30-89 Days Past Due	40	29
Total	40	29
Current	18,567	21,406
Total Loans	18,607	21,435
Total Loans	18,607	21,435
Consumer Secured [Member]
30-89 Days Past Due	81	200
90 Days Or More Past Due	8	17
Total	89	217
Current	11,751	13,997
Total Loans	11,840	14,214
Total Loans	11,840	14,214
Consumer Unsecured [Member]
30-89 Days Past Due	29	61
90 Days Or More Past Due	3	5
Total	32	66
Current	7,124	7,085
Total Loans	7,156	7,151
Total Loans	7,156	7,151
Total [Member]
30-89 Days Past Due	14,594	11,331
90 Days Or More Past Due	38,545	39,237
Total	53,139	50,568
Current	987,300	1,021,540
Total Loans	1,040,439	1,072,108
Total Loans	$ 1,040,439	$ 1,072,108