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				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 1,010,059		$ 1,349,800		$ 1,049,958		$ 1,440,341
Provision for loan losses	10,853		1,330		26,517		61,330
Adjustment for FDIC-supported loans	(5,856)		(162)		(6,913)		(4,676)
Gross loan and lease charge-offs	(73,685)		(142,444)		(153,699)		(310,412)
Recoveries	30,345		29,209		55,853		51,150
Net loan and lease charge-offs	(43,340)		(113,235)		(97,846)		(259,262)
Balance at end of period	971,716		1,237,733		971,716		1,237,733
Balance at beginning of period	98,718		102,168		102,422		111,708
Provision charged (credited) to earnings	4,868		(1,904)		1,164		(11,444)
Balance at end of period	103,586		100,264		103,586		100,264
Allowance for loan losses	971,716		1,237,733		971,716		1,237,733
Reserve for unfunded lending commitments	103,586		100,264		103,586		100,264
Total allowance for credit losses	1,075,302		1,337,997		1,075,302		1,337,997
Commercial [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	631,169		694,090		627,825		761,107
Provision for loan losses	5,733		9,825		32,898		(9,900)
Adjustment for FDIC-supported loans
Gross loan and lease charge-offs	(31,576)		(49,673)		(65,053)		(109,056)
Recoveries	11,033		13,404		20,689		25,495
Net loan and lease charge-offs	(20,543)		(36,269)		(44,364)		(83,561)
Balance at end of period	616,359		667,646		616,359		667,646
Balance at beginning of period	72,002		74,429		77,232		83,352
Provision charged (credited) to earnings	(1,449)		653		(6,679)		(8,270)
Balance at end of period	70,553		75,082		70,553		75,082
Allowance for loan losses	616,359		667,646		616,359		667,646
Reserve for unfunded lending commitments	70,553		75,082		70,553		75,082
Total allowance for credit losses	686,912		742,728		686,912		742,728
Commercial Real Estate [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	248,744		480,514		275,546		487,235
Provision for loan losses	(6,271)		(33,567)		(18,410)		28,295
Adjustment for FDIC-supported loans
Gross loan and lease charge-offs	(22,823)		(64,811)		(49,834)		(138,191)
Recoveries	12,399		10,716		24,747		15,513
Net loan and lease charge-offs	(10,424)		(54,095)		(25,087)		(122,678)
Balance at end of period	232,049		392,852		232,049		392,852
Balance at beginning of period	25,799		26,300		23,572		26,373
Provision charged (credited) to earnings	5,864		(2,448)		8,091		(2,521)
Balance at end of period	31,663		23,852		31,663		23,852
Allowance for loan losses	232,049		392,852		232,049		392,852
Reserve for unfunded lending commitments	31,663		23,852		31,663		23,852
Total allowance for credit losses	263,712		416,704		263,712		416,704
Consumer [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	109,101		148,110		123,115		154,326
Provision for loan losses	12,455		21,990		12,407		37,946
Adjustment for FDIC-supported loans
Gross loan and lease charge-offs	(17,322)		(23,611)		(34,331)		(49,932)
Recoveries	(1,843)		3,284		1,200		7,433
Net loan and lease charge-offs	(19,165)		(20,327)		(33,131)		(42,499)
Balance at end of period	102,391		149,773		102,391		149,773
Balance at beginning of period	917		1,439		1,618		1,983
Provision charged (credited) to earnings	453		(109)		(248)		(653)
Balance at end of period	1,370		1,330		1,370		1,330
Allowance for loan losses	102,391		149,773		102,391		149,773
Reserve for unfunded lending commitments	1,370		1,330		1,370		1,330
Total allowance for credit losses	103,761		151,103		103,761		151,103
FDIC- Supported [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	21,045	[1]	27,086	[1]	23,472	[1]	37,673	[1]
Provision for loan losses	(1,064)	[1]	3,082	[1]	(378)	[1]	4,989	[1]
Adjustment for FDIC-supported loans	(5,856)	[1]	(162)	[1]	(6,913)	[1]	(4,676)	[1]
Gross loan and lease charge-offs	(1,964)	[1]	(4,349)	[1]	(4,481)	[1]	(13,233)	[1]
Recoveries	8,756	[1]	1,805	[1]	9,217	[1]	2,709	[1]
Net loan and lease charge-offs	6,792	[1]	(2,544)	[1]	4,736	[1]	(10,524)	[1]
Balance at end of period	20,917	[1]	27,462	[1]	20,917	[1]	27,462	[1]
Balance at beginning of period	0	[1]	0	[1]	0	[1]	0	[1]
Provision charged (credited) to earnings	0	[1]	0	[1]	0	[1]	0	[1]
Balance at end of period	0	[1]	0	[1]	0	[1]	0	[1]
Allowance for loan losses	20,917	[1]	27,462	[1]	20,917	[1]	27,462	[1]
Reserve for unfunded lending commitments	0	[1]	0	[1]	0	[1]	0	[1]
Total allowance for credit losses	$ 20,917	[1]	$ 27,462	[1]	$ 20,917	[1]	$ 27,462	[1]

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