Note 5 - Loans and Allowance for Loan Losses (Detail) - Activity in the Allowance for Loan Losses (USD $) In Thousands, unless otherwise specified	3 Months Ended																																									3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Commercial and Industrial [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Commercial Real Estate Owner Occupied [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Commercial Real Estate Investor Income Producing [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Acquisition, Construction, and Development Portfolio [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Other Commercial [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Residential Mortgage Loans [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Home Equity Lines of Credit [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Residential Construction [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member] Other Loans to Individuals [Member]	Mar. 31, 2013 Excluding Purchased Credit-Impaired Loans [Member]	Mar. 31, 2013 PCI Loans [Member] Commercial and Industrial [Member]	Mar. 31, 2013 PCI Loans [Member] Commercial Real Estate Investor Income Producing [Member]	Mar. 31, 2013 PCI Loans [Member] Acquisition, Construction, and Development Portfolio [Member]	Mar. 31, 2013 PCI Loans [Member] Other Commercial [Member]	Mar. 31, 2013 PCI Loans [Member] Residential Mortgage Loans [Member]	Mar. 31, 2013 PCI Loans [Member] Home Equity Lines of Credit [Member]	Mar. 31, 2013 PCI Loans [Member] Residential Construction [Member]	Mar. 31, 2013 PCI Loans [Member] Other Loans to Individuals [Member]	Mar. 31, 2013 PCI Loans [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Commercial and Industrial [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Commercial and Industrial [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Commercial Real Estate Owner Occupied [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Commercial Real Estate Owner Occupied [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Commercial Real Estate Investor Income Producing [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Commercial Real Estate Investor Income Producing [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Acquisition, Construction, and Development Portfolio [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Acquisition, Construction, and Development Portfolio [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Other Commercial [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Other Commercial [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Residential Mortgage Loans [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Residential Mortgage Loans [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Home Equity Lines of Credit [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Home Equity Lines of Credit [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Residential Construction [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Residential Construction [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member] Other Loans to Individuals [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member] Other Loans to Individuals [Member]	Mar. 31, 2013 Including Purchased Credit Impaired Loans [Member]	Dec. 31, 2012 Including Purchased Credit Impaired Loans [Member]	Mar. 31, 2013 Commercial and Industrial [Member]	Mar. 31, 2012 Commercial and Industrial [Member]	Mar. 31, 2013 Commercial Real Estate Owner Occupied [Member]	Mar. 31, 2012 Commercial Real Estate Owner Occupied [Member]	Mar. 31, 2013 Commercial Real Estate Investor Income Producing [Member]	Mar. 31, 2012 Commercial Real Estate Investor Income Producing [Member]	Mar. 31, 2013 Acquisition, Construction, and Development Portfolio [Member]	Mar. 31, 2012 Acquisition, Construction, and Development Portfolio [Member]	Mar. 31, 2013 Other Commercial [Member]	Mar. 31, 2012 Other Commercial [Member]	Mar. 31, 2013 Residential Mortgage Loans [Member]	Mar. 31, 2012 Residential Mortgage Loans [Member]	Mar. 31, 2013 Home Equity Lines of Credit [Member]	Mar. 31, 2012 Home Equity Lines of Credit [Member]	Mar. 31, 2013 Residential Construction [Member]	Mar. 31, 2012 Residential Construction [Member]	Mar. 31, 2013 Other Loans to Individuals [Member]	Mar. 31, 2012 Other Loans to Individuals [Member]	Mar. 31, 2012 Unallocated [Member]
Balance, beginning of period	$ 9,624	$ 10,154											$ 225		$ 542		$ 200				$ 967	$ 1,676	$ 1,074	$ 322	$ 496	$ 1,235	$ 1,102	$ 4,603	$ 4,699	$ 6	$ 8	$ 667	$ 654	$ 1,443	$ 1,463	$ 695	$ 1,046	$ 102	$ 49	$ 10,749	$ 10,591	$ 849	$ 703	$ 496	$ 740	$ 1,102	$ 2,106	$ 4,157	$ 3,883	$ 8	$ 17	$ 454	$ 309	$ 1,463	$ 1,898	$ 1,046	$ 455	$ 49	$ 43
Provision for loan losses	309	123	795	(219)	255	(238)	(9)	(122)	35	(649)	25	(127)	(225)	16	(143)	386	118	3	245	36	436																						427		18		(208)		(408)		88		(10)		(35)		117		(16)	150
Charge-offs	(366)	(828)												(16)	(14)	(386)					(416)																					(13)	(169)			(253)	(54)		(345)		(94)	(2)		(82)	(165)			(16)	(1)
Recoveries	631	107																																								45	11	45		131	1	299	81	7		19	1	24		53		8	13
Net charge-offs	265	(721)																																								32	(158)	45		(122)	(53)	299	(264)	7	(94)	17	1	(58)	(165)	53		(8)	12
Balance, end of period	$ 9,762	$ 9,556													$ 385		$ 318	$ 3	$ 245	$ 36	$ 987	$ 1,676	$ 1,074	$ 322	$ 496	$ 1,235	$ 1,102	$ 4,603	$ 4,699	$ 6	$ 8	$ 667	$ 654	$ 1,443	$ 1,463	$ 695	$ 1,046	$ 102	$ 49	$ 10,749	$ 10,591	$ 1,676	$ 972	$ 322	$ 758	$ 1,235	$ 1,845	$ 4,218	$ 3,211	$ 6	$ 11	$ 349	$ 300	$ 1,440	$ 1,698	$ 450	$ 572	$ 66	$ 39	$ 150