Note 6 - Investment Securities (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Note 6 - Investment Securities (Details) [Line Items]
Investment Securities	$ 1,580,000,000		$ 1,590,000,000
Held-to-maturity Securities, Transferred Security, at Carrying Value		722,500,000
Held-to-maturity Securities, Transferred Security, Unrealized Gain (Loss)		40,500,000
Proceeds from Sale of Mortgage Backed Securities (MBS) categorized as Available-for-sale	123,700,000	0
Proceeds from Maturities, Prepayments and Calls of Mortgage Backed Securities (MBS)	20,500,000	98,400,000
Proceeds From Sales and Repayments of Other Investment Securities	16,000,000	320,200,000
Proceeds From Maturities Repayments And Calls Of Held For Investment	112,900,000	10,100,000
Realized Gain From Sale and Call of Investment Securities	6,000,000	6,300,000
Realized Loss From Sale and Call of Investment Securities	67,000	0
Temporarily Impaired Securities As Percentage of Investment Securities	64.40%
Percentage of Unrealized Losses for Securities with Unrealized Losses for Less Than Twelve Months	5.20%
Percentage of Unrealized Losses for Securities with Unrealized Losses for Greater than Twelve Months	3.50%
Pledged Investment Securities	853,600,000		926,500,000
Corporate Bonds Issued By Financial Institutions [Member]
Note 6 - Investment Securities (Details) [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	9
Collateralized Mortgage Backed Securities [Member]
Note 6 - Investment Securities (Details) [Line Items]
Available-for-sale Securities, Gross Unrealized Loss	$ 49,700,000