Consolidated Condensed Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating activities:
Net income	$ 71,530	$ 61,522
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion and amortization	8,457	9,511
Provision for loan losses	43,054	44,454
Other-than-temporary impairment on investment securities		23
Amortization of core deposit intangibles	2,007	2,600
Realized net investment security gains	(25,462)	(11,819)
OREO devaluations	6,478	4,619
Changes in assets and liabilities:
(Increase) in other assets	(35,456)	(30,621)
Increase in other liabilities	6,510	712
Net cash provided by operating activities	77,118	81,001
Investing activities:
Proceeds from sales of available-for-sale securities	535,768	344,325
Proceeds from sales of Federal Home Loan Bank stock	807	111
Proceeds from maturity of:
Available-for-sale securities	351,226	1,354,317
Held-to-maturity securities	281,159	166,321
Purchases of:
Available-for-sale securities	(360,835)	(1,665,825)
Held-to-maturity securities	(429,993)	(77,478)
Net (increase) in loans	(22,149)	(60,036)
Purchases of bank owned life insurance, net	(3,000)	(4,562)
Purchases of premises and equipment, net	(4,765)	(6,579)
Net cash provided by investing activities	348,218	50,594
Financing activities:
Net (decrease) in deposits	(6,233)	(88,022)
Net (decrease) in short-term borrowings	(420,598)	(38,562)
Proceeds from issuance of long-term debt	203,000
Repayment of long-term debt	(16,011)	(11,664)
Cash payment for fractional shares in dividend reinvestment plan	(2)	(2)
Proceeds from reissuance of common stock from treasury shares held		27,568
Cash dividends paid on common and preferred stock	(47,175)	(46,418)
Net cash (used in) financing activities	(287,019)	(157,100)
Increase (decrease) in cash and cash equivalents	138,317	(25,505)
Cash and cash equivalents at beginning of year	133,780	159,091
Cash and cash equivalents at end of period	272,097	133,586
Supplemental disclosures of cash flow information:
Interest	45,401	58,068
Income taxes	16,700	19,200
Non cash activities:
Securities purchased, not yet settled	$ 21,172	$ 148,023