Consolidated Condensed Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net income	$ 51,149	$ 41,945
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion and amortization	5,600	4,524
Provision for loan losses	26,616	29,800
Other-than-temporary impairment on investment securities
Amortization of core deposit intangibles	1,338	1,778
Realized net investment security gains	(21,997)	(11,819)
OREO devaluations	5,890	3,064
Changes in assets and liabilities:
(Increase) in other assets	(38,202)	(18,549)
(Decrease) in other liabilities	(1,666)	(1,757)
Net cash provided by operating activities	28,728	48,986
Investing activities:
Proceeds from sales of available-for-sale securities	319,504	344,325
Proceeds from sales of Federal Home Loan Bank stock	541
Proceeds from maturity of:
Available-for-sale securities	199,940	817,993
Held-to-maturity securities	87,434	42,379
Purchases of:
Available-for-sale securities	(330,839)	(1,086,068)
Held-to-maturity securities	(75,951)	(2,205)
Net (increase) in loans	(24,523)	(41,273)
Purchases of bank owned life insurance, net	(3,000)	(4,562)
Purchases of premises and equipment, net	(4,055)	(3,294)
Net cash provided by investing activities	169,051	67,295
Financing activities:
Net increase (decrease) in deposits	162,097	(19,238)
Net (decrease) in short-term borrowings	(429,557)	(43,462)
Proceeds from issuance of long-term debt	200,000
Repayment of long-term debt	(15,531)	(1,640)
Cash payment for fractional shares in dividend reinvestment plan	(1)	(2)
Proceeds from reissuance of common stock from treasury shares held		21,299
Cash dividends paid on common and preferred stock	(31,451)	(30,784)
Net cash (used in) financing activities	(114,443)	(73,827)
Increase in cash and cash equivalents	83,336	42,454
Cash and cash equivalents at beginning of year	133,780	159,091
Cash and cash equivalents at end of period	217,116	201,545
Supplemental disclosures of cash flow information:
Interest	30,640	40,116
Income taxes	13,700	12,000
Non cash activities:
Securities acquired through payable	$ 113,223	$ 85,980