Note 4 - Investment Securities (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013
Note 4 - Investment Securities (Details) [Line Items]
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		456,400,000	501,100,000	759,700,000
Proceeds from Maturities, Prepayments and Calls of Mortgage Backed Securities (MBS)		213,200,000	118,100,000	108,400,000
Proceeds From Sales and Repayments of Other Investment Securities		575,400,000	61,000,000	525,000,000
Proceeds From Maturities Repayments And Calls Of Held For Investment		231,100,000	552,100,000	435,000,000
Realized Gain From Sale and Call of Investment Securities		29,000,000	18,600,000	21,100,000
Realized Loss From Sale and Call of Investment Securities		1,600,000	607,000	0
Available-for-sale Securities, Gross Unrealized Loss		69,808,000	14,150,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Percentage of Nonperforming Assets		62.00%
Percentage of Unrealized Losses for Securities with Unrealized Losses for Less Than Twelve Months		6.90%
Percentage of Unrealized Losses for Securities with Unrealized Losses for Greater than Twelve Months		4.70%
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year		19
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year		30
Pledged Investment Securities		926,500,000	1,450,000,000
Collateralized Mortgage Backed Securities [Member]
Note 4 - Investment Securities (Details) [Line Items]
Available-for-sale Securities, Gross Unrealized Loss		$ 64,529,000	$ 5,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year		7	6
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year		25	2