Note 4 - Allowance for Loan Losses (Detail) - Allowance For Credit Losses by Impairment Methodology (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Balance - Allowance for Loan Losses	$ 33,921	$ 35,907	$ 34,757	$ 33,677
Allowance for Loan Losses (Member) | Real Estate - Residential Mortgage (Member)
Balance - Allowance for Loan Losses	2,296	2,358
Ending balance: individually evaluated for impairment	401	433
Ending balance: individually evaluated for impairment	401	433
Ending balance: collectively evaluated for impairment	1,895	1,925
Allowance for Loan Losses (Member) | Real Estate Construction [Member]
Balance - Allowance for Loan Losses	345	424
Ending balance: collectively evaluated for impairment	345	424
Allowance for Loan Losses (Member) | commercial, financial and agricultural (Member)
Balance - Allowance for Loan Losses	7,765	9,824
Ending balance: individually evaluated for impairment	674	3,319
Ending balance: individually evaluated for impairment	674	3,319
Ending balance: collectively evaluated for impairment	7,091	6,505
Allowance for Loan Losses (Member) | Equity Lines (Member)
Balance - Allowance for Loan Losses	863	885
Ending balance: collectively evaluated for impairment	863	885
Allowance for Loan Losses (Member) | consumer (Member)
Balance - Allowance for Loan Losses	268	283
Ending balance: individually evaluated for impairment	48	49
Ending balance: individually evaluated for impairment	48	49
Ending balance: collectively evaluated for impairment	220	234
Allowance for Loan Losses (Member) | consumer finance (Member)
Balance - Allowance for Loan Losses	22,384	22,133
Ending balance: collectively evaluated for impairment	22,384	22,133
Allowance for Loan Losses (Member)
Balance - Allowance for Loan Losses	33,921	35,907
Ending balance: individually evaluated for impairment	1,123	3,801
Ending balance: individually evaluated for impairment	1,123	3,801
Ending balance: collectively evaluated for impairment	32,798	32,106
Evaluated loans (Member) | Real Estate - Residential Mortgage (Member)
Balance - Allowance for Loan Losses	151,908	149,257
Ending balance: individually evaluated for impairment	1,844	2,230
Ending balance: individually evaluated for impairment	1,844	2,230
Ending balance: collectively evaluated for impairment	150,064	147,027
Evaluated loans (Member) | Real Estate Construction [Member]
Balance - Allowance for Loan Losses	4,173	5,062
Ending balance: collectively evaluated for impairment	4,173	5,062
Evaluated loans (Member) | commercial, financial and agricultural (Member)
Balance - Allowance for Loan Losses	200,280	205,052
Ending balance: individually evaluated for impairment	4,774	13,938
Ending balance: individually evaluated for impairment	4,774	13,938
Ending balance: collectively evaluated for impairment	195,506	191,114
Evaluated loans (Member) | Equity Lines (Member)
Balance - Allowance for Loan Losses	32,852	33,324
Ending balance: collectively evaluated for impairment	32,852	33,324
Evaluated loans (Member) | consumer (Member)
Balance - Allowance for Loan Losses	5,129	5,309
Ending balance: individually evaluated for impairment	323	324
Ending balance: individually evaluated for impairment	323	324
Ending balance: collectively evaluated for impairment	4,806	4,985
Evaluated loans (Member) | consumer finance (Member)
Balance - Allowance for Loan Losses	280,774	278,186
Ending balance: collectively evaluated for impairment	280,774	278,186
Evaluated loans (Member)
Balance - Allowance for Loan Losses	675,116	676,190
Ending balance: individually evaluated for impairment	6,941	16,492
Ending balance: individually evaluated for impairment	6,941	16,492
Ending balance: collectively evaluated for impairment	668,175	659,698
Real Estate - Residential Mortgage (Member)
Balance - Allowance for Loan Losses	2,296	2,358	2,653	2,379
Real Estate Construction [Member]
Balance - Allowance for Loan Losses	345	424	467	480
commercial, financial and agricultural (Member)
Balance - Allowance for Loan Losses	7,765	9,824	10,410	10,040
Equity Lines (Member)
Balance - Allowance for Loan Losses	863	885	917	912
consumer (Member)
Balance - Allowance for Loan Losses	268	283	269	319
consumer finance (Member)
Balance - Allowance for Loan Losses	$ 22,384	$ 22,133	$ 20,041	$ 19,547