Note 6 - Investment Securities (Details) - The Amortized Costs And Estimated Fair Value Of The Securities Portfolio (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Available For Sale
Available for Sale Securities - Amortized Cost	$ 608,533	$ 618,395
Available for Sale Securities - Gross Unrealized Losses	4,300	12,900
Available for Sale Securities - Estimated Fair Value	616,256	612,820
Held To Maturity
Held to Maturity Securities - Amortized Cost	3,814	765
Held to Maturity Securities - Estimated Fair Value	3,963	827
US Government-sponsored Enterprises Debt Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	98,241	96,750
Available for Sale Securities - Gross Unrealized Gains	292	155
Available for Sale Securities - Gross Unrealized Losses	1,303	3,155
Available for Sale Securities - Estimated Fair Value	97,230	93,750
US States and Political Subdivisions Debt Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	130,947	132,311
Available for Sale Securities - Gross Unrealized Gains	2,920	2,056
Available for Sale Securities - Gross Unrealized Losses	586	2,397
Available for Sale Securities - Estimated Fair Value	133,281	131,970
Held To Maturity
Held to Maturity Securities - Amortized Cost	3,814	765
Held to Maturity Securities - Gross Unrealized Gains	149	62
Held to Maturity Securities - Gross Unrealized Losses	0	0
Held to Maturity Securities - Estimated Fair Value	3,963	827
Residential Mortgage Backed Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	370,687	379,238
Available for Sale Securities - Gross Unrealized Gains	8,777	5,071
Available for Sale Securities - Gross Unrealized Losses	1,945	6,232
Available for Sale Securities - Estimated Fair Value	377,519	378,077
Commercial Mortgage Backed Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	741	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	715	689
Corporate Debt Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	6,925	7,266
Available for Sale Securities - Gross Unrealized Gains	45	40
Available for Sale Securities - Gross Unrealized Losses	478	1,049
Available for Sale Securities - Estimated Fair Value	6,492	6,257
Mutual Funds And Equity Securities [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	992	2,082
Available for Sale Securities - Gross Unrealized Gains	28	15
Available for Sale Securities - Gross Unrealized Losses	1	20
Available for Sale Securities - Estimated Fair Value	1,019	2,077
Total [Member]
Available For Sale
Available for Sale Securities - Amortized Cost	608,533	618,395
Available for Sale Securities - Gross Unrealized Gains	12,062	7,337
Available for Sale Securities - Gross Unrealized Losses	4,339	12,912
Available for Sale Securities - Estimated Fair Value	$ 616,256	$ 612,820