Note 3 - Loans and Allowance for Loan Losses (Detail) - Allowance For Loan Losses And Recorded Investment In Loans By Portfolio Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended							3 Months Ended							3 Months Ended							3 Months Ended							3 Months Ended							3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2012 Commercial And Industrial [Member] Period Beginning [Member]	Dec. 31, 2011 Commercial And Industrial [Member] Period Beginning [Member]	Mar. 31, 2013 Commercial And Industrial [Member] Period Ending [Member]	Mar. 31, 2012 Commercial And Industrial [Member] Period Ending [Member]	Mar. 31, 2013 Commercial And Industrial [Member]	Mar. 31, 2012 Commercial And Industrial [Member]	Dec. 31, 2012 Commercial And Industrial [Member]	Dec. 31, 2012 Real Estate Mortgage [Member] Period Beginning [Member]	Dec. 31, 2011 Real Estate Mortgage [Member] Period Beginning [Member]	Mar. 31, 2013 Real Estate Mortgage [Member] Period Ending [Member]	Mar. 31, 2012 Real Estate Mortgage [Member] Period Ending [Member]	Mar. 31, 2013 Real Estate Mortgage [Member]	Mar. 31, 2012 Real Estate Mortgage [Member]	Dec. 31, 2012 Real Estate Mortgage [Member]	Dec. 31, 2012 Real Estate Construction [Member] Period Beginning [Member]	Dec. 31, 2011 Real Estate Construction [Member] Period Beginning [Member]	Mar. 31, 2013 Real Estate Construction [Member] Period Ending [Member]	Mar. 31, 2012 Real Estate Construction [Member] Period Ending [Member]	Mar. 31, 2013 Real Estate Construction [Member]	Mar. 31, 2012 Real Estate Construction [Member]	Dec. 31, 2012 Real Estate Construction [Member]	Dec. 31, 2012 Consumer And Other [Member] Period Beginning [Member]	Dec. 31, 2011 Consumer And Other [Member] Period Beginning [Member]	Mar. 31, 2013 Consumer And Other [Member] Period Ending [Member]	Mar. 31, 2012 Consumer And Other [Member] Period Ending [Member]	Mar. 31, 2013 Consumer And Other [Member]	Mar. 31, 2012 Consumer And Other [Member]	Dec. 31, 2012 Consumer And Other [Member]	Dec. 31, 2012 Unallocated [Member] Period Beginning [Member]	Dec. 31, 2011 Unallocated [Member] Period Beginning [Member]	Mar. 31, 2013 Unallocated [Member] Period Ending [Member]	Mar. 31, 2012 Unallocated [Member] Period Ending [Member]	Mar. 31, 2013 Unallocated [Member]	Mar. 31, 2012 Unallocated [Member]	Dec. 31, 2012 Period Beginning [Member]	Dec. 31, 2011 Period Beginning [Member]	Mar. 31, 2013 Period Ending [Member]	Mar. 31, 2012 Period Ending [Member]
Allowance for loan losses beginning	$ 24,592			$ 8,255	$ 7,966	$ 7,053	$ 9,223				$ 14,748	$ 19,213	$ 13,217	$ 16,598				$ 216	$ 320	$ 180	$ 235				$ 143	$ 137	$ 79	$ 100				$ 1,230	$ 685	$ 2,303	$ 1,910			$ 24,592	$ 28,321	$ 22,832	$ 28,066
(Reduction in) provision for loan losses	(450)	400						(408)	1,923						(1,031)	(2,638)						(41)	(104)						(43)	(6)						1,073	1,225
Charge-offs	(1,459)	(1,166)						(884)	(784)						(550)	(340)													(25)	(42)
Recoveries	149	511						90	118						50	363						5	19						4	11
Allowance for loan losses ending	22,832			8,255	7,966	7,053	9,223				14,748	19,213	13,217	16,598				216	320	180	235				143	137	79	100				1,230	685	2,303	1,910			24,592	28,321	22,832	28,066
Ending allowance for loan losses balance for loans individually evaluated for impairment	289	1,017							362						289	655
Ending allowance for loan losses balance for loans collectively evaluated for impairment	20,240	25,139						7,053	8,861						12,928	15,943						180	235						79	100
Loans:
Recorded investment in loans	1,127,729	1,050,049	1,103,478					395,911	344,975	383,905					715,033	691,071	702,480					10,112	9,208	9,692					6,673	4,795	7,401
Recorded investment in loans individually evaluated for impairment	21,598	41,744						579	9,315						16,489	29,165						4,530	3,263							1
Recorded investment in loans collectively evaluated for impairment	$ 1,106,131	$ 1,008,305						$ 395,332	$ 335,660						$ 698,544	$ 661,906						$ 5,582	$ 5,945						$ 6,673	$ 4,794