Note 3 - Loans and Allowance for Loan Losses (Detail) - Individually Impaired Loans By Class Of Loans (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Unpaid Principal Balance	$ 68,336	$ 137,743
Recorded Investment With No Allowance	28,221	96,052
Recorded Investment With Allowance	35,668	42,265
Total Recorded Investment	63,889	138,317
Allowance for Loan Losses Allocated	5,143	1,926
Average	87,451	151,772	119,596
Interest Income Recognized	3,103	5,059	4,022
Cash Basis Interest Recognized	3,043	4,923	3,933
Real Estate Construction And Land Development [Member]
Unpaid Principal Balance	26,831	39,762
Recorded Investment With No Allowance	12,712	26,363
Recorded Investment With Allowance	11,068	13,440
Total Recorded Investment	23,780	39,803
Allowance for Loan Losses Allocated	2,075	139
Average	34,880	51,226
Interest Income Recognized	871	719
Cash Basis Interest Recognized	804	716
Real Estate Mortgage Residential [Member]
Unpaid Principal Balance	7,474	30,620
Recorded Investment With No Allowance	2,215	19,129
Recorded Investment With Allowance	5,259	11,603
Total Recorded Investment	7,474	30,732
Allowance for Loan Losses Allocated	1,069	704
Average	13,754	28,732
Interest Income Recognized	333	1,282
Cash Basis Interest Recognized	324	1,271
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
Unpaid Principal Balance	33,491	63,893
Recorded Investment With No Allowance	13,294	47,559
Recorded Investment With Allowance	18,803	16,706
Total Recorded Investment	32,097	64,265
Allowance for Loan Losses Allocated	1,588	894
Average	38,077	67,565
Interest Income Recognized	1,859	2,847
Cash Basis Interest Recognized	1,876	2,768
Commercial And Industrial [Member]
Unpaid Principal Balance	210	3,392
Recorded Investment With No Allowance		2,982
Recorded Investment With Allowance	207	456
Total Recorded Investment	207	3,438
Allowance for Loan Losses Allocated	198	159
Average	403	4,174
Interest Income Recognized	17	205
Cash Basis Interest Recognized	17	164
Consumer Secured [Member]
Unpaid Principal Balance	21	58
Recorded Investment With Allowance	21	60
Total Recorded Investment	21	60
Allowance for Loan Losses Allocated	17	30
Average	66	66
Interest Income Recognized	6	6
Cash Basis Interest Recognized	6	4
Consumer Unsecured [Member]
Unpaid Principal Balance	309	18
Recorded Investment With No Allowance		19
Recorded Investment With Allowance	310
Total Recorded Investment	310	19
Allowance for Loan Losses Allocated	196
Average	271	9
Interest Income Recognized	17
Cash Basis Interest Recognized	$ 16