Note 4 - Debt and Equity Securities (Details) - Gross Unrealized Losses Recorded in AOCI (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Note 4 - Debt and Equity Securities (Details) - Gross Unrealized Losses Recorded in AOCI [Line Items]
Amortized Cost	$ 987,576
Fair Value	984,377		1,017,790
Ending Credit Loss Amount	3,738	3,738	3,738	6,923	6,193	6,178
Credit Related OTTI Charge In The Consolidated Statements Of Income [Member] | Trust Preferred Securities [Member]
Note 4 - Debt and Equity Securities (Details) - Gross Unrealized Losses Recorded in AOCI [Line Items]
Amortized Cost	9,262
Fair Value	6,500
Gross Unrealized Losses Recorded In AOCI	2,762
Ending Credit Loss Amount	3,738
Credit Related OTTI Charge In The Consolidated Statements Of Income [Member]
Note 4 - Debt and Equity Securities (Details) - Gross Unrealized Losses Recorded in AOCI [Line Items]
Amortized Cost	9,262
Fair Value	6,500
Gross Unrealized Losses Recorded In AOCI	2,762
Ending Credit Loss Amount	$ 3,738