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				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 971,716		$ 1,237,733		$ 1,049,958		$ 1,440,341
Provision for loan losses	(1,889)		14,553		24,628		75,883
Adjustment for FDIC-supported loans	(5,908)		(1,520)		(12,821)		(6,196)
Gross loan and lease charge-offs	(58,781)		(129,146)		(212,480)		(439,558)
Recoveries	20,203		27,283		76,056		78,433
Net loan and lease charge-offs	(38,578)		(101,863)		(136,424)		(361,125)
Balance at end of period	925,341		1,148,903		925,341		1,148,903
Balance at beginning of period	103,586		100,264		102,422		111,708
Provision charged (credited) to earnings	2,264		(2,202)		3,428		(13,646)
Balance at end of period	105,850		98,062		105,850		98,062
Allowance for loan losses	925,341		1,148,903		925,341		1,148,903
Reserve for unfunded lending commitments	105,850		98,062		105,850		98,062
Total allowance for credit losses	1,031,191		1,246,965		1,031,191		1,246,965
Commercial [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	616,359		667,646		627,825		761,107
Provision for loan losses	2,843		47,764		35,741		37,864
Adjustment for FDIC-supported loans							0
Gross loan and lease charge-offs	(26,424)		(63,047)		(91,477)		(172,103)
Recoveries	12,013		8,788		32,702		34,283
Net loan and lease charge-offs	(14,411)		(54,259)		(58,775)		(137,820)
Balance at end of period	604,791		661,151		604,791		661,151
Balance at beginning of period	70,553		75,082		77,232		83,352
Provision charged (credited) to earnings	542		1,549		(6,137)		(6,721)
Balance at end of period	71,095		76,631		71,095		76,631
Allowance for loan losses	604,791		661,151		604,791		661,151
Reserve for unfunded lending commitments	71,095		76,631		71,095		76,631
Total allowance for credit losses	675,886		737,782		675,886		737,782
Commercial Real Estate [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	232,049		392,852		275,546		487,235
Provision for loan losses	(5,010)		(49,770)		(17,651)		(21,475)
Adjustment for FDIC-supported loans							0
Gross loan and lease charge-offs	(20,264)		(44,658)		(70,098)		(182,849)
Recoveries	3,312		13,285		22,290		28,798
Net loan and lease charge-offs	(16,952)		(31,373)		(47,808)		(154,051)
Balance at end of period	210,087		311,709		210,087		311,709
Balance at beginning of period	31,663		23,852		23,572		26,373
Provision charged (credited) to earnings	1,741		(3,278)		9,832		(5,799)
Balance at end of period	33,404		20,574		33,404		20,574
Allowance for loan losses	210,087		311,709		210,087		311,709
Reserve for unfunded lending commitments	33,404		20,574		33,404		20,574
Total allowance for credit losses	243,491		332,283		243,491		332,283
Consumer [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	102,391		149,773		123,115		154,326
Provision for loan losses	3,351		15,618		9,989		53,564
Adjustment for FDIC-supported loans							0
Gross loan and lease charge-offs	(11,391)		(18,475)		(45,722)		(68,407)
Recoveries	3,262		3,185		10,231		10,618
Net loan and lease charge-offs	(8,129)		(15,290)		(35,491)		(57,789)
Balance at end of period	97,613		150,101		97,613		150,101
Balance at beginning of period	1,370		1,330		1,618		1,983
Provision charged (credited) to earnings	(19)		(473)		(267)		(1,126)
Balance at end of period	1,351		857		1,351		857
Allowance for loan losses	97,613		150,101		97,613		150,101
Reserve for unfunded lending commitments	1,351		857		1,351		857
Total allowance for credit losses	98,964		150,958		98,964		150,958
FDIC- Supported [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	20,917	[1]	27,462	[1]	23,472	[1]	37,673	[1]
Provision for loan losses	(3,073)	[1]	941	[1]	(3,451)	[1]	5,930	[1]
Adjustment for FDIC-supported loans	(5,908)	[1]	(1,520)	[1]	(12,821)	[1]	(6,196)	[1]
Gross loan and lease charge-offs	(702)	[1]	(2,966)	[1]	(5,183)	[1]	(16,199)	[1]
Recoveries	1,616	[1]	2,025	[1]	10,833	[1]	4,734	[1]
Net loan and lease charge-offs	914	[1]	(941)	[1]	5,650	[1]	(11,465)	[1]
Balance at end of period	12,850	[1]	25,942	[1]	12,850	[1]	25,942	[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	12,850	[1]	25,942	[1]	12,850	[1]	25,942	[1]
Reserve for unfunded lending commitments	0	[1]	0	[1]	0	[1]	0	[1]
Total allowance for credit losses	$ 12,850	[1]	$ 25,942	[1]	$ 12,850	[1]	$ 25,942	[1]

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