Note 3 - Loans (Details) - Classified By Major Type (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned discounts, interest and deferred fees	$ (2,532)		$ (2,590)
Total loans	1,178,288		1,100,337
Allowance for loan losses	(21,832)		(24,592)
Loans, net	1,156,456		1,075,745
Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	438,529		383,641
Percent	37.13%		34.78%
Allowance for loan losses	(7,523)	(7,053)	(8,255)	(9,146)	(9,223)	(7,966)
Real Estate Mortgage Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	36,730		36,807
Percent	3.11%		3.34%
Real Estate Mortgage Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	695,210		665,244
Percent	58.88%		60.32%
Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	731,940		702,051
Percent	61.99%		63.66%
Unearned discounts, interest and deferred fees	(1,445)		(1,595)
Allowance for loan losses	(13,176)	(13,217)	(14,748)	(16,152)	(16,598)	(19,213)
Real Estate Construction Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,016		2,420
Percent	0.17%		0.22%
Real Estate Construction Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,712		7,284
Percent	0.23%		0.66%
Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	4,728		9,704
Percent	0.40%		0.88%
Unearned discounts, interest and deferred fees	(81)		(30)
Allowance for loan losses	(75)	(180)	(216)	(185)	(235)	(320)
Consumer And Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	5,623		7,531
Percent	0.48%		0.68%
Unearned discounts, interest and deferred fees	(160)		(151)
Allowance for loan losses	(70)	(79)	(143)	(104)	(100)	(137)
Variable And Fixed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 1,180,820		$ 1,102,927
Percent	100.00%		100.00%