Note 3 - Loans (Details) - Recorded Investment In Loans By Credit Risk Profile (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Grade	$ 1,181,537	$ 1,103,478	$ 1,097,588
Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	424,013	366,571
Commercial And Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	2,900	4,393
Commercial And Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	11,925	12,941
Commercial And Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	438,838	383,905	376,173
Real Estate Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	664,222	611,159
Real Estate Mortgage [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	21,786	14,593
Real Estate Mortgage [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	46,547	76,728
Real Estate Mortgage [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Real Estate Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	732,555	702,480	708,699
Real Estate Construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	4,665	5,163
Real Estate Construction [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Real Estate Construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	4,529
Real Estate Construction [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	4,665	9,692	7,711
Consumer And Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	5,479	7,401
Consumer And Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Consumer And Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Consumer And Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	0	0
Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	5,479	7,401	5,005
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	1,098,379	990,294
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	24,686	18,986
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	58,472	94,198
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Grade	$ 0	$ 0