Note 3 - Loans (Detail) - Impaired Loans (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Related Allowance		$ 6,100
Related Allowance		6,100
Total
Impaired loans - recorded investment		30,289
Impaired loans - unpaid principal balance		36,388
Impaired loans - related allowance		6,100
Commercial and Industrial [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	1,343	891
Unpaid Principal Balance	1,353	891
Related Allowance	0	0
Related Allowance	0	0
Total
Impaired loans - related allowance	0	0
Commercial and Industrial [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	581	515
Recorded Investment	766	2,273
Unpaid Principal Balance	1,346	2,792
Related Allowance	581	515
Total
Impaired loans - related allowance	581	515
Commercial and Industrial [Member]
Related Allowance	581	515
Related Allowance	581	515
Total
Impaired loans - recorded investment	2,109	3,164
Impaired loans - unpaid principal balance	2,699	3,683
Impaired loans - related allowance	581	515
Commercial Real Estate Other Receivable [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	8,662	9,215
Unpaid Principal Balance	8,659	9,212
Related Allowance	0	0
Related Allowance	0	0
Total
Impaired loans - related allowance	0	0
Commercial Real Estate Other Receivable [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	3,139	2,971
Recorded Investment	8,305	8,377
Unpaid Principal Balance	11,443	11,346
Related Allowance	3,139	2,971
Total
Impaired loans - related allowance	3,139	2,971
Commercial Real Estate Other Receivable [Member]
Related Allowance	3,139	2,971
Related Allowance	3,139	2,971
Total
Impaired loans - recorded investment	16,967	17,592
Impaired loans - unpaid principal balance	20,102	20,558
Impaired loans - related allowance	3,139	2,971
First Lien Residential Mortgage Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Related Allowance	0	0
Total
Impaired loans - related allowance	0	0
First Lien Residential Mortgage Loans [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	2,437	2,298
Recorded Investment	7,638	8,695
Unpaid Principal Balance	10,075	10,993
Related Allowance	2,437	2,298
Total
Impaired loans - related allowance	2,437	2,298
First Lien Residential Mortgage Loans [Member]
Related Allowance	2,437	2,298
Related Allowance	2,437	2,298
Total
Impaired loans - recorded investment	7,638	8,695
Impaired loans - unpaid principal balance	10,075	10,993
Impaired loans - related allowance	2,437	2,298
Junior Lein Residential Mortgage Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Related Allowance	0	0
Total
Impaired loans - related allowance	0	0
Junior Lein Residential Mortgage Loans [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	141	90
Recorded Investment	508	472
Unpaid Principal Balance	649	562
Related Allowance	141	90
Total
Impaired loans - related allowance	141	90
Junior Lein Residential Mortgage Loans [Member]
Related Allowance	141	90
Related Allowance	141	90
Total
Impaired loans - recorded investment	508	472
Impaired loans - unpaid principal balance	649	562
Impaired loans - related allowance	141	90
Consumer Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Related Allowance	0	0
Total
Impaired loans - related allowance	0	0
Consumer Loans [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	55	226
Recorded Investment	190	366
Unpaid Principal Balance	244	592
Related Allowance	55	226
Total
Impaired loans - related allowance	55	226
Consumer Loans [Member]
Related Allowance	55	226
Related Allowance	55	226
Total
Impaired loans - recorded investment	190	366
Impaired loans - unpaid principal balance	244	592
Impaired loans - related allowance	55	226
No Allocated Allowance [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment	10,005
Unpaid Principal Balance	10,012
Related Allowance	0
Related Allowance	0
Total
Impaired loans - related allowance	0
No Allocated Allowance [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance	6,353
Recorded Investment	17,407
Unpaid Principal Balance	23,757
Related Allowance	6,353
Total
Impaired loans - related allowance	6,353
No Allocated Allowance [Member]
Related Allowance	6,353
Related Allowance	6,353
Total
Impaired loans - recorded investment	27,412
Impaired loans - unpaid principal balance	33,769
Impaired loans - related allowance	6,353
Period End Loans No Allocated Allowance For Loan Losses [Member]
Recorded Investment		10,106
Unpaid Principal Balance		10,103
Related Allowance		0
Related Allowance		0
Total
Impaired loans - related allowance		0
Period End Loans Allocated Allowance Loan Losses [Member]
Related Allowance		6,100
Recorded Investment		20,183
Unpaid Principal Balance		26,285
Related Allowance		6,100
Total
Impaired loans - related allowance		$ 6,100