Note 8 - Loans and Allowance for Loan Losses (Detail) - Individually Impaired Loans By Class Of Loans (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Unpaid Principal Balance	$ 67,868	$ 68,336
Recorded Investment With No Allowance	30,196	28,221
Recorded Investment With Allowance	33,554	35,668
Total Recorded Investment	63,750	63,889
Allowance for Loan Losses Allocated	4,741	5,143
Real Estate Construction And Land Development [Member]
Unpaid Principal Balance	26,523	26,831
Recorded Investment With No Allowance	11,568	12,712
Recorded Investment With Allowance	12,289	11,068
Total Recorded Investment	23,857	23,780
Allowance for Loan Losses Allocated	1,887	2,075
Real Estate Mortgage Residential [Member]
Unpaid Principal Balance	8,138	7,474
Recorded Investment With No Allowance	2,796	2,215
Recorded Investment With Allowance	5,370	5,259
Total Recorded Investment	8,166	7,474
Allowance for Loan Losses Allocated	1,067	1,069
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
Unpaid Principal Balance	32,308	33,491
Recorded Investment With No Allowance	15,432	13,294
Recorded Investment With Allowance	15,393	18,803
Total Recorded Investment	30,825	32,097
Allowance for Loan Losses Allocated	1,425	1,588
Commercial And Industrial [Member]
Unpaid Principal Balance	667	210
Recorded Investment With No Allowance	400
Recorded Investment With Allowance	268	207
Total Recorded Investment	668	207
Allowance for Loan Losses Allocated	245	198
Consumer Secured [Member]
Unpaid Principal Balance	21	21
Recorded Investment With Allowance	21	21
Total Recorded Investment	21	21
Allowance for Loan Losses Allocated	17	17
Consumer Unsecured [Member]
Unpaid Principal Balance	211	309
Recorded Investment With Allowance	213	310
Total Recorded Investment	213	310
Allowance for Loan Losses Allocated	$ 100	$ 196