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	Sep. 30, 2012	Dec. 31, 2011
Total Loans	$ 1,018,311	$ 1,072,108
Total Loans	1,018,311	1,072,108
Real Estate Construction And Land Development [Member]
30-89 Days Past Due	104	3,343
90 Days Or More Past Due	10,224	18,970
Total	10,328	22,313
Current	104,996	97,676
Total Loans	115,324	119,989
Total Loans	115,324	119,989
Real Estate Mortgage Residential [Member]
30-89 Days Past Due	2,298	5,836
90 Days Or More Past Due	4,430	7,352
Total	6,728	13,188
Current	406,556	432,276
Total Loans	413,284	445,464
Total Loans	413,284	445,464
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
30-89 Days Past Due	537	1,684
90 Days Or More Past Due	14,631	12,497
Total	15,168	14,181
Current	362,528	370,150
Total Loans	377,696	384,331
Total Loans	377,696	384,331
Commercial And Industrial [Member]
30-89 Days Past Due	99	98
90 Days Or More Past Due	462	300
Total	561	398
Current	47,891	48,373
Total Loans	48,452	48,771
Total Loans	48,452	48,771
States and Political Subdivisions [Member]
Current	22,489	23,601
Total Loans	22,489	23,601
Total Loans	22,489	23,601
Lease Financing [Member]
30-89 Days Past Due	8	80
90 Days Or More Past Due	162	96
Total	170	176
Current	3,179	6,976
Total Loans	3,349	7,152
Total Loans	3,349	7,152
Commercial Other [Member]
30-89 Days Past Due	39	29
90 Days Or More Past Due	5
Total	44	29
Current	18,988	21,406
Total Loans	19,032	21,435
Total Loans	19,032	21,435
Consumer Secured [Member]
30-89 Days Past Due	67	200
90 Days Or More Past Due	10	17
Total	77	217
Current	12,077	13,997
Total Loans	12,154	14,214
Total Loans	12,154	14,214
Consumer Unsecured [Member]
30-89 Days Past Due	138	61
90 Days Or More Past Due		5
Total	138	66
Current	6,393	7,085
Total Loans	6,531	7,151
Total Loans	6,531	7,151
Total [Member]
30-89 Days Past Due	3,290	11,331
90 Days Or More Past Due	29,924	39,237
Total	33,214	50,568
Current	985,097	1,021,540
Total Loans	1,018,311	1,072,108
Total Loans	$ 1,018,311	$ 1,072,108