Note 18 - Fair Value Measurements (Detail) - Carrying Amount of Assets Measured at Fair Value on a Nonrecurring Basis (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Real Estate Construction And Land Development OREO [Member] | Fair Value, Inputs, Level 3 [Member]
OREO
Fair Value	$ 15,873	$ 8,826
Real Estate Construction And Land Development OREO [Member]
OREO
Fair Value	15,873	8,826
Residential Real Estate OREO [Member] | Fair Value, Inputs, Level 3 [Member]
OREO
Fair Value	1,483	1,217
Residential Real Estate OREO [Member]
OREO
Fair Value	1,483	1,217
Farmland and Other Commercial Enterprises OREO [Member] | Fair Value, Inputs, Level 3 [Member]
OREO
Fair Value	3,826	4,785
Farmland and Other Commercial Enterprises OREO [Member]
OREO
Fair Value	3,826	4,785
Total [Member] | Fair Value, Inputs, Level 3 [Member]
OREO
Fair Value	21,182	14,828
Total [Member]
OREO
Fair Value	21,182	14,828
Real Estate Construction And Land Development [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	17,921	18,636
Real Estate Construction And Land Development [Member]
Impaired Loans
Fair Value	17,921	18,636
Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	2,273	6,824
Real Estate Mortgage Residential [Member]
Impaired Loans
Fair Value	2,273	6,824
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	3,523	14,264
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
Impaired Loans
Fair Value	3,523	14,264
Commercial And Industrial [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	9	293
Commercial And Industrial [Member]
Impaired Loans
Fair Value	9	293
Consumer Secured [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	4
Consumer Secured [Member]
Impaired Loans
Fair Value	4
Consumer Unsecured [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	113
Consumer Unsecured [Member]
Impaired Loans
Fair Value	113
Total [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	23,843	40,064
Total [Member]
Impaired Loans
Fair Value	23,843	40,064
Consumer Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value		47
Consumer Portfolio Segment [Member]
Impaired Loans
Fair Value		47
Fair Value, Inputs, Level 3 [Member]
Impaired Loans
Fair Value	$ 979,301	$ 1,043,824