Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	$ 424,716	$ 138,539
Available for sale securities, less than 12 months, unrealized losses	(14,322)	(758)
Available for sale securities, 12 months or longer, fair value	59,930	41,305
Available for sale securities, 12 months or longer, unrealized losses	(2,934)	(840)
Available for sale securities, total, fair value	484,646	179,844
Available for sale securities, total, unrealized losses	(17,256)	(1,598)
Held to Maturity securities, less than 12 months, fair value	610,771	96,635
Held to Maturity securities, less than 12 months, unrealized losses	(20,688)	(1,591)
Held to Maturity securities, 12 months or longer, fair value	78,939	14,292
Held to Maturity securities, 12 months or longer, unrealized losses	(7,209)	(215)
Held to Maturity securities, total, fair value	689,710	110,927
Held to Maturity securities, total, unrealized losses	(27,897)	(1,806)
US Treasury Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	2,994
Available for sale securities, less than 12 months, unrealized losses	(3)
Available for sale securities, total, fair value	2,994
Available for sale securities, total, unrealized losses	(3)
US Government-sponsored Enterprises Debt Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	91,669	9,983
Available for sale securities, less than 12 months, unrealized losses	(663)	(17)
Available for sale securities, total, fair value	91,669	9,983
Available for sale securities, total, unrealized losses	(663)	(17)
Held to Maturity securities, less than 12 months, fair value	1,597
Held to Maturity securities, less than 12 months, unrealized losses	(4)
Held to Maturity securities, total, fair value	1,597
Held to Maturity securities, total, unrealized losses	(4)
Residential Mortgage Backed Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	864	103
Available for sale securities, less than 12 months, unrealized losses	(15)	(1)
Available for sale securities, 12 months or longer, fair value		11
Available for sale securities, total, fair value	864	114
Available for sale securities, total, unrealized losses	(15)	(1)
Held to Maturity securities, less than 12 months, fair value	38,396	113
Held to Maturity securities, less than 12 months, unrealized losses	(616)
Held to Maturity securities, 12 months or longer, fair value	392	664
Held to Maturity securities, 12 months or longer, unrealized losses	(8)	(10)
Held to Maturity securities, total, fair value	38,788	777
Held to Maturity securities, total, unrealized losses	(624)	(10)
Commercial Mortgage Backed Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	1,072
Available for sale securities, less than 12 months, unrealized losses	(5)
Available for sale securities, total, fair value	1,072
Available for sale securities, total, unrealized losses	(5)
US States and Political Subdivisions Debt Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	17,516	2,080
Available for sale securities, less than 12 months, unrealized losses	(222)	(23)
Available for sale securities, 12 months or longer, fair value	3,214	8,928
Available for sale securities, 12 months or longer, unrealized losses	(101)	(229)
Available for sale securities, total, fair value	20,730	11,008
Available for sale securities, total, unrealized losses	(323)	(252)
Held to Maturity securities, less than 12 months, fair value	355,797	69,839
Held to Maturity securities, less than 12 months, unrealized losses	(14,893)	(1,205)
Held to Maturity securities, 12 months or longer, fair value	64,427	4,275
Held to Maturity securities, 12 months or longer, unrealized losses	(6,774)	(30)
Held to Maturity securities, total, fair value	420,224	74,114
Held to Maturity securities, total, unrealized losses	(21,667)	(1,235)
Residential Collateralized Mortgage Obligations [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	187,848	72,803
Available for sale securities, less than 12 months, unrealized losses	(12,326)	(294)
Available for sale securities, 12 months or longer, fair value	40,575
Available for sale securities, 12 months or longer, unrealized losses	(2,398)
Available for sale securities, total, fair value	228,423	72,803
Available for sale securities, total, unrealized losses	(14,724)	(294)
Held to Maturity securities, less than 12 months, fair value	214,981	26,683
Held to Maturity securities, less than 12 months, unrealized losses	(5,175)	(386)
Held to Maturity securities, 12 months or longer, fair value	14,120	9,353
Held to Maturity securities, 12 months or longer, unrealized losses	(427)	(175)
Held to Maturity securities, total, fair value	229,101	36,036
Held to Maturity securities, total, unrealized losses	(5,602)	(561)
Asset-backed Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	5,002
Available for sale securities, less than 12 months, unrealized losses	(1)
Available for sale securities, 12 months or longer, fair value	4,475	5,828
Available for sale securities, 12 months or longer, unrealized losses	(100)	(143)
Available for sale securities, total, fair value	9,477	5,828
Available for sale securities, total, unrealized losses	(101)	(143)
Domestic Corporate Debt Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, less than 12 months, fair value	117,751	53,570
Available for sale securities, less than 12 months, unrealized losses	(1,087)	(423)
Available for sale securities, 12 months or longer, fair value	9,824	24,597
Available for sale securities, 12 months or longer, unrealized losses	(177)	(403)
Available for sale securities, total, fair value	127,575	78,167
Available for sale securities, total, unrealized losses	(1,264)	(826)
Other Securities [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, 12 months or longer, fair value	1,842	1,940
Available for sale securities, 12 months or longer, unrealized losses	(158)	(60)
Available for sale securities, total, fair value	1,842	1,940
Available for sale securities, total, unrealized losses	(158)	(60)
FHLMC And FNMA Stock [Member]
Note 2 - Investment Securities (Details) - Gross Unrealized Losses, Investment Securities Portfolio [Line Items]
Available for sale securities, 12 months or longer, fair value		1
Available for sale securities, 12 months or longer, unrealized losses		(5)
Available for sale securities, total, fair value		1
Available for sale securities, total, unrealized losses		$ (5)