Note 6 - Loans and Allowance for Credit Losses (Details) - Loans and Leases by Credit Quality Indicator (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	$ 3,279,429	$ 2,945,158	$ 2,691,358
Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	695,191	655,409	590,451
Commercial Loan [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	14,015	29,327	29,765
Commercial Loan [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	17,405	9,614	16,407
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	726,611	694,350	636,623
Commercial Real Estate Investment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	1,286,730	1,095,285	966,886
Commercial Real Estate Investment [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	12,836	21,833	31,277
Commercial Real Estate Investment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	2,913	2,682	5,560
Commercial Real Estate Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	1,302,479	1,119,800	1,003,723
Commercial Real Estate Owner Occupied [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	313,523	294,337	284,507
Commercial Real Estate Owner Occupied [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	13,320	15,580	18,248
Commercial Real Estate Owner Occupied [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	3,230	7,574	8,580
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	330,073	317,491	311,335
Residential Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	122,681	89,501	77,969
Residential Mortgage [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	906	804	844
Residential Mortgage [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income		113
Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	123,587	90,418	78,813
Home Equity Line of Credit [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	106,468	107,415	105,854
Home Equity Line of Credit [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	1,902	2,145	2,150
Home Equity Line of Credit [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	561	682	561
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	108,931	110,242	108,565
Consumer, Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	7,116	3,961	7,970
Consumer, Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income		70	11
Consumer, Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	7,116	4,031	7,981
Construction Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	654,631	575,321	502,319
Construction Loans [Member] | Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	13,119	19,643	23,120
Construction Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	12,882	13,862	18,879
Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	680,632	608,826	544,318
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	3,186,340	2,821,229	2,535,956
Watch and Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	56,098	89,332	105,404
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans And Leases Receivable Net Of Deferred Income	$ 36,991	$ 34,597	$ 49,998