Note 3 - Loans (Detail) - Allowance for Credit Losses and Recorded Investment in Financing Receivables (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Beginning balance	$ 21,522	$ 21,327	$ 21,019	$ 21,431
Provision for loan losses	1,364	3,459	6,352	10,726
Loans charged off	(1,974)	(4,009)	(6,891)	(11,719)
Recoveries	420	606	852	945
Ending balance	21,332	21,383	21,332	21,383
Ending balance: individually evaluated for impairment	3,800	3,693	3,800	3,693
Ending balance: collectively evaluated for impairment	17,532	17,690	17,532	17,690
Ending balance	977,410	989,053	977,410	989,053	983,909
Ending balance: individually evaluated for impairment	25,300	30,850	25,300	30,850
Ending balance: collectively evaluated for impairment	952,110	958,203	952,110	958,203
Commercial and Industrial [Member]
Beginning balance	2,404	2,732	2,485	3,024
Provision for loan losses	(238)	1,380	81	1,855
Loans charged off	(110)	(579)	(535)	(1,468)
Recoveries	34	36	59	158
Ending balance	2,090	3,569	2,090	3,569
Ending balance: individually evaluated for impairment	321	1,311	321	1,311
Ending balance: collectively evaluated for impairment	1,769	2,258	1,769	2,258
Ending balance	152,259	159,340	152,259	159,340
Ending balance: individually evaluated for impairment	2,675	4,445	2,675	4,445
Ending balance: collectively evaluated for impairment	149,584	154,895	149,584	154,895
Commercial Real Estate Portfolio Segment [Member]
Beginning balance	11,215	11,596	11,534	12,375
Provision for loan losses	817	774	3,059	4,379
Loans charged off	(956)	(2,476)	(3,605)	(6,903)
Recoveries	277	410	365	453
Ending balance	11,353	10,304	11,353	10,304
Ending balance: individually evaluated for impairment	3,479	2,382	3,479	2,382
Ending balance: collectively evaluated for impairment	7,874	7,922	7,874	7,922
Ending balance	479,577	480,012	479,577	480,012
Ending balance: individually evaluated for impairment	22,625	26,405	22,625	26,405
Ending balance: collectively evaluated for impairment	456,952	453,607	456,952	453,607
First Lien Residential Mortgage Loans [Member]
Beginning balance	5,643	4,672	5,393	3,960
Provision for loan losses	845	1,108	2,138	3,544
Loans charged off	(571)	(706)	(1,744)	(2,470)
Recoveries	35	72	165	112
Ending balance	5,952	5,146	5,952	5,146
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	5,952	5,146	5,952	5,146
Ending balance	215,893	202,273	215,893	202,273
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	215,893	202,273	215,893	202,273
Junior Lein Residential Mortgage Loans [Member]
Beginning balance	523	554	505	774
Provision for loan losses	229	35	533	(72)
Loans charged off	(174)	(35)	(460)	(148)
Recoveries	0	0	0	0
Ending balance	578	554	578	554
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	578	554	578	554
Ending balance	60,661	70,404	60,661	70,404
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	60,661	70,404	60,661	70,404
Consumer Portfolio Segment [Member]
Beginning balance	851	1,197	931	1,162
Provision for loan losses	94	86	209	504
Loans charged off	(163)	(213)	(547)	(730)
Recoveries	74	88	263	222
Ending balance	856	1,158	856	1,158
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	856	1,158	856	1,158
Ending balance	69,020	77,024	69,020	77,024
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	69,020	77,024	69,020	77,024
Unallocated Financing Receivables [Member]
Beginning balance	886	576	171	136
Provision for loan losses	(383)	76	332	516
Loans charged off	0	0	0	0
Recoveries	0	0	0	0
Ending balance	503	652	503	652
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	503	652	503	652
Ending balance	0	0	0	0
Ending balance: individually evaluated for impairment	0	0	0	0
Ending balance: collectively evaluated for impairment	$ 0	$ 0	$ 0	$ 0