Note 9 - Borrowed Funds (Details) (USD $)	9 Months Ended				9 Months Ended								9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014 Callable Securities [Member]	Sep. 30, 2014 Securities Sold under Agreements to Repurchase [Member] London Interbank Offered Rate (LIBOR) [Member] Maximum [Member]	Jun. 30, 2014 Securities Sold Under Agreements to Repurchase Minimum [Member]	Jun. 30, 2014 Securities Sold Under Agreements to Repurchase Maximum Initial Rate [Member]	Sep. 30, 2014 Floating to Fixed Rate Agreements Totaling $300 Million [Member] Maximum [Member]	Sep. 30, 2014 Floating to Fixed Rate Agreements Totaling $300 Million [Member] Minimum [Member]	Sep. 30, 2014 Floating to Fixed Rate Agreements Totaling $300 Million [Member]	Sep. 30, 2014 Securities Sold under Agreements to Repurchase [Member]	Dec. 31, 2013 Securities Sold under Agreements to Repurchase [Member]	Sep. 30, 2014 London Interbank Offered Rate (LIBOR) [Member] Minimum [Member]	Sep. 30, 2014 Minimum [Member]
Note 9 - Borrowed Funds (Details) [Line Items]
Securities Sold under Agreements to Repurchase (in Dollars)	$ 550,000,000	$ 800,000,000		$ 350,000,000
Weighted Average Rate Of Securities Sold Under Agreements	3.78%	3.87%
Prepaid Security Sold Under Repurchase Agreement (in Dollars)	100,000,000		300,000,000
Rate of Prepaid Security Sold Under Repurchase Agreements	3.50%		3.97%
Prepayment Penalty Security Sold Under Agreements To Repurchase (in Dollars)	3,400,000		15,700,000
Number Of Floating-To-Fixed Rate Agreements										4
Total Floating To Fixed Rate (in Dollars)										200,000,000
Debt Instrument, Basis Spread on Variable Rate					3.40%								3.50%
Debt Instrument, Interest Rate, Stated Percentage						1.00%	3.50%	5.07%	4.89%					8.00%
Number Of Fixed-To-Floating Security Sold Under Agreements To Repurchase	3
Total Fixed To Floating Rate Agreements (in Dollars)	150,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	0.00%
Investment Securities Pledged As Collateral (in Dollars)											629,300,000	906,100,000
Advances from Federal Home Loan Banks (in Dollars)	$ 555,000,000	$ 521,200,000
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Weighted Average Interest Rate	0.12%	0.17%