Note 4 - Loans and Allowance for Credit Losses (Detail) - Recorded Investment In The Company's Loans And Leases (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Loans And Leases Receivable Net Of Deferred Income	$ 2,397,669	$ 2,056,256	$ 2,029,645
Pass [Member] | Commercial Loan [Member]
Loans And Leases Receivable Net Of Deferred Income	493,361	438,943	426,834
Pass [Member] | Commercial Real Estate Investment [Member]
Loans And Leases Receivable Net Of Deferred Income	920,553	739,668	753,767
Pass [Member] | Commercial Real Estate Owner Occupied [Member]
Loans And Leases Receivable Net Of Deferred Income	285,292	235,988	232,236
Pass [Member] | Residential Mortgage [Member]
Loans And Leases Receivable Net Of Deferred Income	57,952	38,801	37,662
Pass [Member] | Home Equity Line of Credit [Member]
Loans And Leases Receivable Net Of Deferred Income	96,674	96,740	93,584
Pass [Member] | Consumer, Other [Member]
Loans And Leases Receivable Net Of Deferred Income	4,990	2,882	4,210
Pass [Member] | Construction Loans [Member]
Loans And Leases Receivable Net Of Deferred Income	397,246	394,135	368,926
Pass [Member]
Loans And Leases Receivable Net Of Deferred Income	2,256,068	1,947,157	1,917,219
Special Mention [Member] | Commercial Loan [Member]
Loans And Leases Receivable Net Of Deferred Income	26,718	28,202	30,909
Special Mention [Member] | Commercial Real Estate Investment [Member]
Loans And Leases Receivable Net Of Deferred Income	10,593	7,673	10,038
Special Mention [Member] | Commercial Real Estate Owner Occupied [Member]
Loans And Leases Receivable Net Of Deferred Income	14,401	8,906	8,754
Special Mention [Member] | Home Equity Line of Credit [Member]
Loans And Leases Receivable Net Of Deferred Income	1,586
Special Mention [Member] | Consumer, Other [Member]
Loans And Leases Receivable Net Of Deferred Income	45
Special Mention [Member] | Construction Loans [Member]
Loans And Leases Receivable Net Of Deferred Income	19,337	8,679	7,793
Special Mention [Member]
Loans And Leases Receivable Net Of Deferred Income	72,680	53,460	57,494
Substandard [Member] | Commercial Loan [Member]
Loans And Leases Receivable Net Of Deferred Income	14,037	11,704	12,127
Substandard [Member] | Commercial Real Estate Investment [Member]
Loans And Leases Receivable Net Of Deferred Income	11,624	9,304	8,923
Substandard [Member] | Commercial Real Estate Owner Occupied [Member]
Loans And Leases Receivable Net Of Deferred Income	6,455	5,280	4,507
Substandard [Member] | Residential Mortgage [Member]
Loans And Leases Receivable Net Of Deferred Income		751
Substandard [Member] | Home Equity Line of Credit [Member]
Loans And Leases Receivable Net Of Deferred Income	670	363	424
Substandard [Member] | Consumer, Other [Member]
Loans And Leases Receivable Net Of Deferred Income	8	1,345	8
Substandard [Member] | Construction Loans [Member]
Loans And Leases Receivable Net Of Deferred Income	36,110	26,855	28,710
Substandard [Member]
Loans And Leases Receivable Net Of Deferred Income	68,904	55,602	54,699
Doubtful [Member] | Commercial Loan [Member]
Loans And Leases Receivable Net Of Deferred Income	17	37	233
Doubtful [Member]
Loans And Leases Receivable Net Of Deferred Income	17	37	233
Commercial Loan [Member]
Loans And Leases Receivable Net Of Deferred Income	534,133	478,886	470,103
Commercial Real Estate Investment [Member]
Loans And Leases Receivable Net Of Deferred Income	942,770	756,645	772,728
Commercial Real Estate Owner Occupied [Member]
Loans And Leases Receivable Net Of Deferred Income	306,148	250,174	245,497
Residential Mortgage [Member]
Loans And Leases Receivable Net Of Deferred Income	57,952	39,552	37,662
Home Equity Line of Credit [Member]
Loans And Leases Receivable Net Of Deferred Income	98,930	97,103	94,008
Consumer, Other [Member]
Loans And Leases Receivable Net Of Deferred Income	5,043	4,227	4,218
Construction Loans [Member]
Loans And Leases Receivable Net Of Deferred Income	$ 452,693	$ 429,669	$ 405,429