Note 5 - Loans and Allowance for Credit Losses - Loans Past Due (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	$ 1,173	$ 4,130
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	495	1,364
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	2,986	4,940
Commercial Portfolio Segment [Member]
Loans past due	4,654	10,434
Current loans	1,125,388	1,041,823
Total recorded investment in loans	1,130,042	1,052,257
Income Producing Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due		2,841
Income Producing Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due
Income Producing Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	10,098	5,961
Income Producing Portfolio Segment [Member]
Loans past due	10,098	8,802
Current loans	2,541,088	2,106,676
Total recorded investment in loans	2,551,186	2,115,478
Owner Occupied Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due		3,189
Owner Occupied Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	3,338	902
Owner Occupied Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	2,103	1,268
Owner Occupied Portfolio Segment [Member]
Loans past due	5,441	5,359
Current loans	584,986	492,744
Total recorded investment in loans	590,427	498,103
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	164
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	562	329
Residential Portfolio Segment [Member]
Loans past due	726	329
Current loans	153,713	147,036
Total recorded investment in loans	154,439	147,365
Construction Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due
Construction Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due		5,020
Construction Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	6,412	557
Construction Portfolio Segment [Member]
Loans past due	6,412	5,577
Current loans	936,401	1,059,799
Total recorded investment in loans	942,813	1,065,376
Home Equity Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	562
Home Equity Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	620	77
Home Equity Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	113	161
Home Equity Portfolio Segment [Member]
Loans past due	1,295	238
Current loans	105,561	112,647
Total recorded investment in loans	106,856	112,885
Other Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	8	56
Other Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	16	60
Other Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due		23
Other Consumer Portfolio Segment [Member]
Loans past due	24	139
Current loans	6,188	6,765
Total recorded investment in loans	6,212	6,904
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	1,743	10,216
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	4,633	7,423
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	22,274	13,239
Loans past due	28,650	30,878
Current loans	5,453,325	4,967,490
Total recorded investment in loans	$ 5,481,975	$ 4,998,368