Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	$ 613,004	$ 618,395
Available for Sale Securities - Gross Unrealized Gains	10,222	7,337
Available for Sale Securities - Gross Unrealized Losses	4,851	12,912
Available for Sale Securities - Estimated Fair Value	618,375	612,820
Held to Maturity Securities - Amortized Cost	3,801	765
Held to Maturity Securities - Estimated Fair Value	3,977	827
US Government-sponsored Enterprises Debt Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	99,069	96,750
Available for Sale Securities - Gross Unrealized Gains	241	155
Available for Sale Securities - Gross Unrealized Losses	1,436	3,155
Available for Sale Securities - Estimated Fair Value	97,874	93,750
US States and Political Subdivisions Debt Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	133,097	132,311
Available for Sale Securities - Gross Unrealized Gains	2,936	2,056
Available for Sale Securities - Gross Unrealized Losses	443	2,397
Available for Sale Securities - Estimated Fair Value	135,590	131,970
Held to Maturity Securities - Amortized Cost	3,801	765
Held to Maturity Securities - Gross Unrealized Gains	176	62
Held to Maturity Securities - Gross Unrealized Losses	0	0
Held to Maturity Securities - Estimated Fair Value	3,977	827
Residential Mortgage Backed Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	372,455	379,238
Available for Sale Securities - Gross Unrealized Gains	7,002	5,071
Available for Sale Securities - Gross Unrealized Losses	2,636	6,232
Available for Sale Securities - Estimated Fair Value	376,821	378,077
Commercial Mortgage Backed Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	737	748
Available for Sale Securities - Gross Unrealized Gains	0	0
Available for Sale Securities - Gross Unrealized Losses	26	59
Available for Sale Securities - Estimated Fair Value	711	689
Corporate Debt Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	6,728	7,266
Available for Sale Securities - Gross Unrealized Gains	34	40
Available for Sale Securities - Gross Unrealized Losses	303	1,049
Available for Sale Securities - Estimated Fair Value	6,459	6,257
Mutual Funds And Equity Securities [Member]
Note 6 - Investment Securities (Details) - The Amortized Costs and Estimated Fair Value of the Securities Portfolio [Line Items]
Available for Sale Securities - Amortized Cost	918	2,082
Available for Sale Securities - Gross Unrealized Gains	9	15
Available for Sale Securities - Gross Unrealized Losses	7	20
Available for Sale Securities - Estimated Fair Value	$ 920	$ 2,077