Note 4 - Loans and Allowance for Loan Losses (Detail) - Loans restructured as TDRs, excluding loans acquired, segregated by class of loans: (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Balance Prior to TDR	$ 2,327	$ 2,488
Balance at December 31	2,104	2,460
Consumer Loans [Member] | Restructured During Current Period [Member] | Other Consumer [Member]
Number of Loans	1	4
Consumer Loans [Member] | Restructured During Current Period [Member] | Total Consumer [Member]
Number of Loans	1	4
Consumer Loans [Member] | Change in Maturity Date [Member] | Other Consumer [Member]
Balance at December 31		16
Consumer Loans [Member] | Change in Maturity Date [Member] | Total Consumer [Member]
Balance at December 31		16
Consumer Loans [Member] | Change in Rate [Member] | Other Consumer [Member]
Balance at December 31	33
Consumer Loans [Member] | Change in Rate [Member] | Total Consumer [Member]
Balance at December 31	33
Consumer Loans [Member] | Other Consumer [Member]
Balance Prior to TDR	48	30
Balance at December 31	33	16
Consumer Loans [Member] | Total Consumer [Member]
Balance Prior to TDR	48	30
Balance at December 31	33	16
Real Estate Loans [Member] | Restructured During Current Period [Member] | Construction [Member]
Number of Loans	1
Real Estate Loans [Member] | Restructured During Current Period [Member] | Other Commercial [Member]
Number of Loans	5
Real Estate Loans [Member] | Restructured During Current Period [Member] | Total Real Estate [Member]
Number of Loans	6	4
Real Estate Loans [Member] | Restructured During Current Period [Member] | Other Commercial Real Estate Loans [Member]
Number of Loans		4
Real Estate Loans [Member] | Change in Maturity Date [Member] | Other Commercial [Member]
Balance at December 31	653
Real Estate Loans [Member] | Change in Maturity Date [Member] | Total Real Estate [Member]
Balance at December 31	653	2,112
Real Estate Loans [Member] | Change in Maturity Date [Member] | Other Commercial Real Estate Loans [Member]
Balance at December 31		2,112
Real Estate Loans [Member] | Change in Rate [Member] | Construction [Member]
Balance at December 31	51
Real Estate Loans [Member] | Change in Rate [Member] | Other Commercial [Member]
Balance at December 31	1,328
Real Estate Loans [Member] | Change in Rate [Member] | Total Real Estate [Member]
Balance at December 31	1,379
Real Estate Loans [Member] | Construction [Member]
Balance Prior to TDR	51
Balance at December 31	51
Real Estate Loans [Member] | Other Commercial [Member]
Balance Prior to TDR	2,178
Balance at December 31	1,981
Real Estate Loans [Member] | Total Real Estate [Member]
Balance Prior to TDR	2,229	2,112
Balance at December 31	2,032	2,112
Real Estate Loans [Member] | Other Commercial Real Estate Loans [Member]
Balance Prior to TDR		2,112
Balance at December 31		2,112
Commercial Loans [Member] | Restructured During Current Period [Member] | Commercial [Member]
Number of Loans	1	2
Commercial Loans [Member] | Restructured During Current Period [Member] | Total Commercial [Member]
Number of Loans	1	2
Commercial Loans [Member] | Change in Maturity Date [Member] | Commercial [Member]
Balance at December 31		332
Commercial Loans [Member] | Change in Maturity Date [Member] | Total Commercial [Member]
Balance at December 31		332
Commercial Loans [Member] | Change in Rate [Member] | Commercial [Member]
Balance at December 31	39
Commercial Loans [Member] | Change in Rate [Member] | Total Commercial [Member]
Balance at December 31	39
Commercial Loans [Member] | Commercial [Member]
Balance Prior to TDR	50	346
Balance at December 31	39	332
Commercial Loans [Member] | Total Commercial [Member]
Balance Prior to TDR	50	346
Balance at December 31	39	332
Restructured During Current Period [Member]
Number of Loans	8	10
Change in Maturity Date [Member]
Balance at December 31	653	2,460
Change in Rate [Member]
Balance at December 31	$ 1,451