Note 8 - Loans and Allowance for Loan Losses (Detail) - Past Due Loans 30 Days Or More By Class Of Loans (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Total Loans	$ 1,017,977	$ 1,004,995
Real Estate Construction And Land Development [Member]
30-89 Days Past Due	106	908
90 Days Or More Past Due	567	1,361
Total	673	2,269
Current	102,541	100,185
Total Loans	103,214	102,454
Real Estate Mortgage Residential [Member]
30-89 Days Past Due	1,327	2,303
90 Days Or More Past Due	2,666	2,500
Total	3,993	4,803
Current	369,901	363,959
Total Loans	373,894	368,762
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
30-89 Days Past Due	1,731	1,990
90 Days Or More Past Due	12,038	10,724
Total	13,769	12,714
Current	419,358	412,763
Total Loans	433,127	425,477
Commercial And Industrial [Member]
30-89 Days Past Due	123	108
90 Days Or More Past Due	453	53
Total	576	161
Current	47,019	46,651
Total Loans	47,595	46,812
States and Political Subdivisions [Member]
Current	23,329	21,472
Total Loans	23,329	21,472
Lease Financing [Member]
30-89 Days Past Due	19	1
90 Days Or More Past Due	47	53
Total	66	54
Current	2,076	2,561
Total Loans	2,142	2,615
Commercial Other [Member]
30-89 Days Past Due	51	38
90 Days Or More Past Due		399
Total	51	437
Current	17,580	18,719
Total Loans	17,631	19,156
Consumer Secured [Member]
30-89 Days Past Due	98	69
90 Days Or More Past Due	23
Total	121	69
Current	10,731	11,663
Total Loans	10,852	11,732
Consumer Unsecured [Member]
30-89 Days Past Due	66	137
Total	66	137
Current	6,127	6,378
Total Loans	6,193	6,515
Total [Member]
30-89 Days Past Due	3,521	5,554
90 Days Or More Past Due	15,794	15,090
Total	19,315	20,644
Current	998,662	984,351
Total Loans	$ 1,017,977	$ 1,004,995