Note 6 - Loans and Allowance for Credit Losses (Details) - Loans Past Due (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	$ 10,106	$ 3,502
Loans 60-89 Days Past Due	9,116	13,641
Loans 90 Days or More Past Due	22,507	24,702
Total Past Due Loans	41,729	41,845
Current Loans	3,237,700	2,903,313
Total Recorded Investment in Loans	3,279,429	2,945,158
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	3,739	1,698
Loans 60-89 Days Past Due	477	11,146
Loans 90 Days or More Past Due	8,671	6,779
Total Past Due Loans	12,887	19,623
Current Loans	713,724	674,727
Total Recorded Investment in Loans	726,611	694,350
Commercial Real Estate Investment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	5,080	818
Loans 60-89 Days Past Due	1,596
Loans 90 Days or More Past Due	2,676	2,525
Total Past Due Loans	9,352	3,343
Current Loans	1,293,127	1,116,457
Total Recorded Investment in Loans	1,302,479	1,119,800
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	318	360
Loans 60-89 Days Past Due	282	2,121
Loans 90 Days or More Past Due	3,230	5,452
Total Past Due Loans	3,830	7,933
Current Loans	326,243	309,558
Total Recorded Investment in Loans	330,073	317,491
Real Estate Mortgage Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	681
Loans 90 Days or More Past Due	650	887
Total Past Due Loans	1,331	887
Current Loans	122,256	89,531
Total Recorded Investment in Loans	123,587	90,418
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	284	626
Loans 60-89 Days Past Due	739	359
Loans 90 Days or More Past Due	403	623
Total Past Due Loans	1,426	1,608
Current Loans	107,505	108,634
Total Recorded Investment in Loans	108,931	110,242
Consumer, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	4
Loans 60-89 Days Past Due	17	15
Loans 90 Days or More Past Due		70
Total Past Due Loans	21	85
Current Loans	7,095	3,946
Total Recorded Investment in Loans	7,116	4,031
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 60-89 Days Past Due	6,005
Loans 90 Days or More Past Due	6,877	8,366
Total Past Due Loans	12,882	8,366
Current Loans	667,750	600,460
Total Recorded Investment in Loans	$ 680,632	$ 608,826