Note 4 - Loans and Allowance for Credit Losses (Details) - Aging Analysis and the Recorded Investments in Loans Past Due (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	$ 6,612	$ 13,117
Loans 60-89 Days Past Due	2,182	6,810
Loans 90 Days or More Past Due	27,546	30,684
Total Past Due Loans	36,340	50,611
Current Loans	2,760,500	2,442,484
Total Recorded Investment in Loans	2,796,840	2,493,095
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	3,067	3,784
Loans 60-89 Days Past Due	980	598
Loans 90 Days or More Past Due	7,607	4,799
Total Past Due Loans	11,654	9,181
Current Loans	670,759	535,889
Total Recorded Investment in Loans	682,413	545,070
Commercial Real Estate Investment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	93	1,538
Loans 60-89 Days Past Due		992
Loans 90 Days or More Past Due	3,081	3,458
Total Past Due Loans	3,174	5,988
Current Loans	1,036,601	908,650
Total Recorded Investment in Loans	1,039,775	914,638
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	362	369
Loans 60-89 Days Past Due	781	4,081
Loans 90 Days or More Past Due	6,426	2,578
Total Past Due Loans	7,569	7,028
Current Loans	326,509	290,829
Total Recorded Investment in Loans	334,078	297,857
Real Estate Mortgage Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 60-89 Days Past Due	100	107
Loans 90 Days or More Past Due	895	699
Total Past Due Loans	995	806
Current Loans	78,066	61,065
Total Recorded Investment in Loans	79,061	61,871
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	818	1,150
Loans 60-89 Days Past Due	296	352
Loans 90 Days or More Past Due	511	513
Total Past Due Loans	1,625	2,015
Current Loans	107,264	104,829
Total Recorded Investment in Loans	108,889	106,844
Consumer, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 60-89 Days Past Due	25	5
Loans 90 Days or More Past Due	45	43
Total Past Due Loans	70	48
Current Loans	9,289	4,237
Total Recorded Investment in Loans	9,359	4,285
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	2,272	6,276
Loans 60-89 Days Past Due		675
Loans 90 Days or More Past Due	8,981	18,594
Total Past Due Loans	11,253	25,545
Current Loans	532,012	536,985
Total Recorded Investment in Loans	$ 543,265	$ 562,530