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	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	$ 4,663	$ 3,502
Loans 60-89 Days Past Due	5,802	13,641
Loans 90 Days or More Past Due	36,327	24,702
Total Past Due Loans	46,792	41,845
Current Loans	3,017,183	2,903,313
Total Recorded Investment in Loans	3,063,975	2,945,158
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	635	1,698
Loans 60-89 Days Past Due	3,943	11,146
Loans 90 Days or More Past Due	17,646	6,779
Total Past Due Loans	22,224	19,623
Current Loans	682,162	674,727
Total Recorded Investment in Loans	704,386	694,350
Commercial Real Estate Investment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	1,305	818
Loans 60-89 Days Past Due	70
Loans 90 Days or More Past Due	2,271	2,525
Total Past Due Loans	3,646	3,343
Current Loans	1,192,759	1,116,457
Total Recorded Investment in Loans	1,196,405	1,119,800
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	1,951	360
Loans 60-89 Days Past Due		2,121
Loans 90 Days or More Past Due	7,323	5,452
Total Past Due Loans	9,274	7,933
Current Loans	311,720	309,558
Total Recorded Investment in Loans	320,994	317,491
Real Estate Mortgage Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 90 Days or More Past Due	771	887
Total Past Due Loans	771	887
Current Loans	97,075	89,531
Total Recorded Investment in Loans	97,846	90,418
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	769	626
Loans 60-89 Days Past Due	872	359
Loans 90 Days or More Past Due	598	623
Total Past Due Loans	2,239	1,608
Current Loans	106,600	108,634
Total Recorded Investment in Loans	108,839	110,242
Consumer, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	3
Loans 60-89 Days Past Due		15
Loans 90 Days or More Past Due	60	70
Total Past Due Loans	63	85
Current Loans	5,995	3,946
Total Recorded Investment in Loans	6,058	4,031
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 60-89 Days Past Due	917
Loans 90 Days or More Past Due	7,658	8,366
Total Past Due Loans	8,575	8,366
Current Loans	620,872	600,460
Total Recorded Investment in Loans	$ 629,447	$ 608,826