Note 7 - Loans and Allowance for Loan Losses (Detail) - Individually Impaired Loans By Class Of Loans (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Recorded Investment	$ 42,496	$ 96,052
Unpaid Principal Balance	52,510	95,575
Recorded Investment	36,672	42,265
Unpaid Principal Balance	36,599	42,168
Allowance For Loan Losses Allocated	4,158	1,926
Real Estate Construction And Land Development [Member]
Recorded Investment	22,576	26,363
Unpaid Principal Balance	30,405	26,337
Recorded Investment	10,733	13,440
Unpaid Principal Balance	10,700	13,425
Allowance For Loan Losses Allocated	696	139
Real Estate Mortgage Residential [Member]
Recorded Investment	4,060	22,923
Unpaid Principal Balance	4,578	22,843
Recorded Investment	6,179	13,239
Unpaid Principal Balance	6,164	13,197
Allowance For Loan Losses Allocated	1,303	998
Real Estate Mortgage Farmland And Other Commercial Enterprises [Member]
Recorded Investment	15,860	43,765
Unpaid Principal Balance	17,527	43,438
Recorded Investment	19,211	15,070
Unpaid Principal Balance	19,191	15,035
Allowance For Loan Losses Allocated	1,735	600
Commercial And Industrial [Member]
Recorded Investment		2,982
Unpaid Principal Balance		2,939
Recorded Investment	250	456
Unpaid Principal Balance	247	453
Allowance For Loan Losses Allocated	244	159
Consumer Secured [Member]
Recorded Investment	22	60
Unpaid Principal Balance	22	58
Allowance For Loan Losses Allocated	18	30
Consumer Unsecured [Member]
Recorded Investment		19
Unpaid Principal Balance		18
Recorded Investment	277
Unpaid Principal Balance	275
Allowance For Loan Losses Allocated	$ 162