Note 8 - Loans and Allowance for Loan Losses (Detail) - Risk Category of Loans by Class (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Loans	$ 1,017,977	$ 1,004,995
Real Estate Construction And Land Development [Member] | Pass [Member]
Loans	74,747	68,721
Real Estate Construction And Land Development [Member] | Special Mention [Member]
Loans	7,121	7,562
Real Estate Construction And Land Development [Member] | Substandard [Member]
Loans	21,306	26,171
Real Estate Construction And Land Development [Member] | Doubtful [Member]
Loans	40
Real Estate Construction And Land Development [Member] | Total [Member]
Loans	103,214	102,454
Real Estate Construction And Land Development [Member]
Loans	103,214	102,454
Real Estate Mortgage Residential [Member] | Pass [Member]
Loans	332,632	328,214
Real Estate Mortgage Residential [Member] | Special Mention [Member]
Loans	18,190	18,485
Real Estate Mortgage Residential [Member] | Substandard [Member]
Loans	23,072	21,984
Real Estate Mortgage Residential [Member] | Doubtful [Member]
Loans		79
Real Estate Mortgage Residential [Member] | Total [Member]
Loans	373,894	368,762
Real Estate Mortgage Residential [Member]
Loans	373,894	368,762
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Pass [Member]
Loans	358,480	348,918
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Special Mention [Member]
Loans	32,551	35,027
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Substandard [Member]
Loans	42,048	41,532
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Doubtful [Member]
Loans	48
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Total [Member]
Loans	433,127	425,477
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
Loans	433,127	425,477
Commercial And Industrial [Member] | Pass [Member]
Loans	42,678	41,527
Commercial And Industrial [Member] | Special Mention [Member]
Loans	3,519	4,201
Commercial And Industrial [Member] | Substandard [Member]
Loans	1,322	1,008
Commercial And Industrial [Member] | Doubtful [Member]
Loans	76	76
Commercial And Industrial [Member] | Total [Member]
Loans	47,595	46,812
Commercial And Industrial [Member]
Loans	47,595	46,812
States and Political Subdivisions [Member] | Pass [Member]
Loans	23,329	21,472
States and Political Subdivisions [Member] | Total [Member]
Loans	23,329	21,472
States and Political Subdivisions [Member]
Loans	23,329	21,472
Lease Financing [Member] | Pass [Member]
Loans	2,095	2,615
Lease Financing [Member] | Substandard [Member]
Loans	47
Lease Financing [Member] | Total [Member]
Loans	2,142	2,615
Lease Financing [Member]
Loans	2,142	2,615
Commercial Other [Member] | Pass [Member]
Loans	17,136	18,592
Commercial Other [Member] | Special Mention [Member]
Loans	481	559
Commercial Other [Member] | Substandard [Member]
Loans	14	5
Commercial Other [Member] | Total [Member]
Loans	17,631	19,156
Commercial Other [Member]
Loans	$ 17,631	$ 19,156