Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
OPERATING ACTIVITIES:
Net income	$ 204,836		$ 196,576
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	18,961		39,372
Provision for depreciation and amortization	32,565		35,281
Amortization of investment security premiums, net	29,989		9,406
Investment securities gains, net	(8,556)	[1]	(5,870)	[1]
Net gains on sales of loans held for sale	(376)		(1,554)
Originations of loans held for sale	0		(41,231)
Proceeds from sales of loans held for sale	22,649		67,065
Net increase in trading securities	5,454		(2,941)
Stock-based compensation	3,705		3,614
(Increase) decrease in interest receivable	4,728		(1,077)
Decrease in interest payable	(1,067)		(4,393)
Increase in income taxes payable	(5,571)		14,863
Net tax benefit related to equity compensation plans	(1,233)		(1,025)
Other changes, net	(10,718)		3,011
Net cash provided by operating activities	295,366		311,097
INVESTING ACTIVITIES:
Proceeds from sales of investment securities	14,931	[1]	11,699	[1]
Proceeds from maturities/pay downs of investment securities	2,341,083	[1]	1,968,848	[1]
Purchases of investment securities	(2,036,260)	[1]	(2,926,445)	[1]
Net (increase) decrease in loans	(489,628)		288,987
Long-term securities purchased under agreements to resell	(125,000)		(500,000)
Repayments of long-term securities purchased under agreements to resell	125,000		100,000
Purchases of land, buildings and equipment	(19,243)		(16,135)
Sales of land, buildings and equipment	2,338		2,288
Net cash used in investing activities	(186,779)		(1,070,758)
FINANCING ACTIVITIES:
Net increase in non-interest bearing, savings, interest checking and money market deposits	554,167		1,090,342
Net decrease in time open and C.D.'s	(479,383)		(150,511)
Net increase in short-term federal funds purchased and securities sold under agreements to repurchase	1,868		74,901
Repayment of long-term borrowings	(8,073)		(404)
Purchases of treasury stock	(75,536)		(101,111)
Issuance of stock under stock purchase and equity compensation plans	9,766		14,060
Net tax benefit related to equity compensation plans	1,233		1,025
Cash dividends paid on common stock	(60,819)		(59,636)
Net cash provided by financing activities	(56,777)		868,666
Increase (decrease) in cash and cash equivalents	51,810		109,005
Cash and cash equivalents at beginning of year	517,551		460,675
Cash and cash equivalents at September 30	569,361		569,680
Supplemental Cash Flow Information:
Income tax payments, net	104,175		76,795
Interest paid on deposits and borrowings	30,198		44,828
Loans transferred to foreclosed real estate	$ 7,178		$ 20,630

[1] Available for sale and non-marketable securities