Loans And Allowance For Credit Losses (Summary Of Changes In The Allowance For Credit Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 1,049,958		$ 1,440,341
Provision for loan losses	15,664		60,000
Adjustment for FDIC-supported loans	(1,057)		(9,048)
Gross loan and lease charge-offs	(80,014)		(167,968)
Net charge-offs recoverable from FDIC			4,534
Recoveries	25,508		21,941
Net loan and lease charge-offs	(54,506)		(141,493)
Balance at end of period	1,010,059		1,349,800
Balance at beginning of period	102,422		111,708
Provision charged (credited) to earnings	(3,704)		(9,540)
Balance at end of period	98,718		102,168
Allowance for loan losses	1,010,059		1,349,800
Reserve for unfunded lending commitments	98,718		102,168
Total allowance for credit losses	1,108,777		1,451,968
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	627,825		761,107
Provision for loan losses	27,165		(19,725)
Gross loan and lease charge-offs	(33,477)		(59,383)
Recoveries	9,656		12,091
Net loan and lease charge-offs	(23,821)		(47,292)
Balance at end of period	631,169		694,090
Balance at beginning of period	77,232		83,352
Provision charged (credited) to earnings	(5,230)		(8,923)
Balance at end of period	72,002		74,429
Allowance for loan losses	631,169		694,090
Reserve for unfunded lending commitments	72,002		74,429
Total allowance for credit losses	703,171		768,519
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	275,546		487,235
Provision for loan losses	(12,139)		61,862
Gross loan and lease charge-offs	(27,011)		(73,380)
Recoveries	12,348		4,797
Net loan and lease charge-offs	(14,663)		(68,583)
Balance at end of period	248,744		480,514
Balance at beginning of period	23,572		26,373
Provision charged (credited) to earnings	2,227		(73)
Balance at end of period	25,799		26,300
Allowance for loan losses	248,744		480,514
Reserve for unfunded lending commitments	25,799		26,300
Total allowance for credit losses	274,543		506,814
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	123,115		154,326
Provision for loan losses	(48)		15,956
Gross loan and lease charge-offs	(17,009)		(26,321)
Recoveries	3,043		4,149
Net loan and lease charge-offs	(13,966)		(22,172)
Balance at end of period	109,101		148,110
Balance at beginning of period	1,618		1,983
Provision charged (credited) to earnings	(701)		(544)
Balance at end of period	917		1,439
Allowance for loan losses	109,101		148,110
Reserve for unfunded lending commitments	917		1,439
Total allowance for credit losses	110,018		149,549
FDIC- Supported [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	23,472	[1]	37,673	[1]
Provision for loan losses	686	[1]	1,907	[1]
Adjustment for FDIC-supported loans	(1,057)	[1]	(9,048)	[1]
Gross loan and lease charge-offs	(2,517)	[1]	(8,884)	[1]
Net charge-offs recoverable from FDIC			4,534	[1]
Recoveries	461	[1]	904	[1]
Net loan and lease charge-offs	(2,056)	[1]	(3,446)	[1]
Balance at end of period	21,045	[1]	27,086	[1]
Allowance for loan losses	21,045	[1]	27,086	[1]
Total allowance for credit losses	$ 21,045	[1]	$ 27,086	[1]

[1] The Purchased Loans section following contains further discussion related to FDIC-supported loans.