Note 3 - Loans (Detail) - Impaired Loans (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Impaired loans with no allocated allowance for loan losses - related allowance		$ 3,875
Impaired loans with allocated allowance for loan losses - related allowance		3,875
Total
Impaired loans - recorded investment		38,008
Impaired loans - unpaid principal balance		50,756
Impaired loans - related allowance		3,875
Commercial and Industrial [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	3,659	4,358
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	3,658	5,846
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - related allowance	0	0
Commercial and Industrial [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	180	253
Impaired loans with allocated allowance for loan losses - recorded investment	439	720
Impaired loans with allocated allowance for loan losses - unpaid principal balance	618	998
Impaired loans with allocated allowance for loan losses - related allowance	180	253
Total
Impaired loans - related allowance	180	253
Commercial and Industrial [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	180	253
Impaired loans with allocated allowance for loan losses - related allowance	180	253
Total
Impaired loans - recorded investment	4,098	5,078
Impaired loans - unpaid principal balance	4,276	6,844
Impaired loans - related allowance	180	253
Commercial Real Estate Other Receivable [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	8,314	11,940
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	8,312	16,987
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - 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]
Impaired loans with no allocated allowance for loan losses - related allowance	2,952	3,622
Impaired loans with allocated allowance for loan losses - recorded investment	11,134	10,423
Impaired loans with allocated allowance for loan losses - unpaid principal balance	14,084	15,225
Impaired loans with allocated allowance for loan losses - related allowance	2,952	3,622
Total
Impaired loans - related allowance	2,952	3,622
Commercial Real Estate Other Receivable [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	2,952	3,622
Impaired loans with allocated allowance for loan losses - related allowance	2,952	3,622
Total
Impaired loans - recorded investment	19,448	22,363
Impaired loans - unpaid principal balance	22,396	32,212
Impaired loans - related allowance	2,952	3,622
First Lien Residential Mortgage Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	9,510	10,079
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	9,510	11,120
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - 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]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - recorded investment	0	0
Impaired loans with allocated allowance for loan losses - unpaid principal balance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - related allowance	0	0
First Lien Residential Mortgage Loans [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - recorded investment	9,510	10,079
Impaired loans - unpaid principal balance	9,510	11,120
Impaired loans - related allowance	0	0
Junior Lein Residential Mortgage Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	450	278
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	450	331
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - 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]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - recorded investment	0	0
Impaired loans with allocated allowance for loan losses - unpaid principal balance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - related allowance	0	0
Junior Lein Residential Mortgage Loans [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - recorded investment	450	278
Impaired loans - unpaid principal balance	450	331
Impaired loans - related allowance	0	0
Consumer Loans [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	516	210
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	516	249
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - related allowance	0	0
Consumer Loans [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - recorded investment	0	0
Impaired loans with allocated allowance for loan losses - unpaid principal balance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - related allowance	0	0
Consumer Loans [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	0	0
Impaired loans with allocated allowance for loan losses - related allowance	0	0
Total
Impaired loans - recorded investment	516	210
Impaired loans - unpaid principal balance	516	249
Impaired loans - related allowance	0	0
No Allocated Allowance [Member] | Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment	22,449
Impaired loans with no allocated allowance for loan losses - unpaid principal balance	22,446
Impaired loans with no allocated allowance for loan losses - related allowance	0
Impaired loans with allocated allowance for loan losses - related allowance	0
Total
Impaired loans - related allowance	0
No Allocated Allowance [Member] | Period End Loans Allocated Allowance Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	3,132
Impaired loans with allocated allowance for loan losses - recorded investment	11,573
Impaired loans with allocated allowance for loan losses - unpaid principal balance	14,702
Impaired loans with allocated allowance for loan losses - related allowance	3,132
Total
Impaired loans - related allowance	3,132
No Allocated Allowance [Member]
Impaired loans with no allocated allowance for loan losses - related allowance	3,132
Impaired loans with allocated allowance for loan losses - related allowance	3,132
Total
Impaired loans - recorded investment	34,022
Impaired loans - unpaid principal balance	37,148
Impaired loans - related allowance	3,132
Period End Loans No Allocated Allowance For Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - recorded investment		26,865
Impaired loans with no allocated allowance for loan losses - unpaid principal balance		34,533
Impaired loans with no allocated allowance for loan losses - related allowance		0
Impaired loans with allocated allowance for loan losses - related allowance		0
Total
Impaired loans - related allowance		0
Period End Loans Allocated Allowance Loan Losses [Member]
Impaired loans with no allocated allowance for loan losses - related allowance		3,875
Impaired loans with allocated allowance for loan losses - recorded investment		11,143
Impaired loans with allocated allowance for loan losses - unpaid principal balance		16,223
Impaired loans with allocated allowance for loan losses - related allowance		3,875
Total
Impaired loans - related allowance		$ 3,875