Note 3 - Loans (Detail) - Allowance for Credit Losses and Recorded Investment in Financing Receivables (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Provision for loan losses	$ 1,278	$ 2,494
Ending balance	961,318		963,762
Commercial and Industrial [Member]
Beginning balance	1,896	2,485
Provision for loan losses	74	3
Loans charged off	(50)	(129)
Recoveries	18	10
Ending balance	1,938	2,369
Ending balance: individually evaluated for impairment	581	253
Ending balance: collectively evaluated for impairment	1,357	2,116
Ending balance	151,057	157,725
Ending balance: individually evaluated for impairment	2,699	4,013
Ending balance: collectively evaluated for impairment	148,358	153,712
Commercial Real Estate Portfolio Segment [Member]
Beginning balance	11,565	11,534
Provision for loan losses	775	1,525
Loans charged off	(927)	(1,340)
Recoveries	61	48
Ending balance	11,474	11,767
Ending balance: individually evaluated for impairment	3,139	3,399
Ending balance: collectively evaluated for impairment	8,335	8,368
Ending balance	471,495	481,592
Ending balance: individually evaluated for impairment	20,102	24,979
Ending balance: collectively evaluated for impairment	451,393	456,613
First Lien Residential Mortgage Loans [Member]
Beginning balance	5,656	5,393
Provision for loan losses	397	707
Loans charged off	(770)	(583)
Recoveries	31	46
Ending balance	5,314	5,563
Ending balance: individually evaluated for impairment	2,437	2,167
Ending balance: collectively evaluated for impairment	2,877	3,396
Ending balance	215,926	212,994
Ending balance: individually evaluated for impairment	10,075	10,014
Ending balance: collectively evaluated for impairment	205,851	202,980
Junior Lein Residential Mortgage Loans [Member]
Beginning balance	555	505
Provision for loan losses	46	221
Loans charged off	(55)	(194)
Recoveries	0	0
Ending balance	546	532
Ending balance: individually evaluated for impairment	141	106
Ending balance: collectively evaluated for impairment	405	426
Ending balance	56,335	64,303
Ending balance: individually evaluated for impairment	649	609
Ending balance: collectively evaluated for impairment	55,686	63,694
Consumer Portfolio Segment [Member]
Beginning balance	805	931
Provision for loan losses	(57)	165
Loans charged off	(153)	(249)
Recoveries	75	98
Ending balance	670	945
Ending balance: individually evaluated for impairment	55	186
Ending balance: collectively evaluated for impairment	615	759
Ending balance	66,277	65,698
Ending balance: individually evaluated for impairment	244	485
Ending balance: collectively evaluated for impairment	66,033	65,213
Unallocated Financing Receivables [Member]
Beginning balance	863	171
Provision for loan losses	43	(127)
Loans charged off	0	0
Recoveries	0	0
Ending balance	906	44
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	906	44
Ending balance	0	0
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	0	0
Allowance for Credit Losses [Member]
Beginning balance	21,340	21,019
Provision for loan losses	1,278	2,494
Loans charged off	(1,955)	(2,495)
Recoveries	185	202
Ending balance	20,848	21,220
Ending balance: individually evaluated for impairment	6,353	6,111
Ending balance: collectively evaluated for impairment	14,495	15,109
Ending balance	961,090	982,312
Ending balance: individually evaluated for impairment	33,769	40,100
Ending balance: collectively evaluated for impairment	$ 927,321	$ 942,212