Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities:
Net income	$ 177,764	$ 162,121
Adjustments to reconcile net income to net cash from operating activities:
Provision for loan losses	5,955	27,445
Deferred tax expense (benefit)	(5,020)	(137)
Accretion of loan discounts	(8,321)	(9,865)
Securities premium amortization (discount accretion), net	14,952	7,590
Net (gain) loss on securities transactions	121	(6,414)
Depreciation and amortization	28,374	28,082
Net loss on sale/write-down of assets/foreclosed assets	4,182	4,240
Stock-based compensation	7,942	10,016
Net tax benefit (deficiency) from stock-based compensation	(535)	(89)
Excess tax benefits from stock-based compensation	(110)	(393)
Earnings on life insurance policies	(3,042)	(2,977)
Net change in:
Trading account securities	(1,214)	(722)
Accrued interest receivable and other assets	53,120	41,588
Accrued interest payable and other liabilities	(4,945)	(1,145)
Net cash from operating activities	269,223	259,340
Securities held to maturity:
Purchases		(83,184)
Maturities, calls and principal repayments	766	464
Securities available for sale:
Purchases	(17,484,661)	(6,195,375)
Sales	15,987,480	5,587,391
Maturities, calls and principal repayments	617,489	587,650
Net change in loans	(823,627)	(17,748)
Net cash paid in acquisitions	(7,199)	(1,044)
Proceeds from sales of premises and equipment	3,765	1,256
Purchases of premises and equipment	(19,724)	(23,266)
Proceeds from sales of repossessed properties	10,715	11,825
Net cash from investing activities	(1,714,996)	(132,031)
Financing Activities:
Net change in deposits	1,488,449	1,584,531
Net change in short-term borrowings	(120,998)	182,573
Principal payments on long-term borrowings	(14)	(150,014)
Proceeds from stock option exercises	10,092	7,239
Excess tax benefits from stock-based compensation	110	393
Purchase of treasury stock		(1,657)
Cash dividends paid	(87,282)	(83,990)
Net cash from financing activities	1,290,357	1,539,075
Net change in cash and cash equivalents	(155,416)	1,666,384
Cash and equivalents at beginning of period	2,907,592	2,820,977
Cash and equivalents at end of period	$ 2,752,176	$ 4,487,361