Loans And Allowance For Credit Losses (Summary Of ALLL And Outstanding Loan Balances According To The Company's Impairment Method) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012		Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 1,329,179		$ 1,008,923		$ 1,336,098		$ 937,433
Impaired Financing Receivable, Interest Income, Accrual Method	25,242		18,776		94,456		48,208
Allowance for loan losses: Individually evaluated for impairment	(67,256)				(67,256)						(66,640)
Allowance for loan losses: Collectively evaluated for impairment	725,143				725,143						817,322
Allowance for loan losses: Purchased loans with evidence of credit deterioration	5,124				5,124						12,125
Allowance for loan losses: Total	797,523		927,068		797,523		927,068		813,912		896,087		973,443		1,051,685
Outstanding loan balances: Individually evaluated for impairment	756,354				756,354						904,496
Outstanding loan balances: Collectively evaluated for impairment	37,183,125				37,183,125						36,291,555
Outstanding loan balances: Purchased loans with evidence of credit deterioration	333,251				333,251						469,196
Total loans	38,272,730				38,272,730						37,665,247
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	199,217		133,120		175,040		128,930
Impaired Financing Receivable, Interest Income, Accrual Method	1,105		830		2,594		2,395
Total loans	11,904,477				11,904,477						11,256,945
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	217,439		187,072		211,225		168,328
Impaired Financing Receivable, Interest Income, Accrual Method	915		558		2,810		1,729
Total loans	7,378,586				7,378,586						7,589,082
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(39,950)				(39,950)						(30,587)
Allowance for loan losses: Collectively evaluated for impairment	439,325				439,325						480,321
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0						0
Allowance for loan losses: Total	479,275		523,435		479,275		523,435		486,353		510,908		542,170		561,351
Outstanding loan balances: Individually evaluated for impairment	327,999				327,999						353,380
Outstanding loan balances: Collectively evaluated for impairment	19,778,832				19,778,832						19,409,343
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0						0
Total loans	20,106,831				20,106,831						19,762,723
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(15,117)				(15,117)						(22,295)
Allowance for loan losses: Collectively evaluated for impairment	228,891				228,891						254,681
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0						0
Allowance for loan losses: Total	244,008		293,170		244,008		293,170		251,278		276,976		307,965		343,747
Outstanding loan balances: Individually evaluated for impairment	322,996				322,996						437,647
Outstanding loan balances: Collectively evaluated for impairment	9,845,839				9,845,839						9,564,585
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0						0
Total loans	10,168,835				10,168,835						10,002,232
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(12,189)				(12,189)						(13,758)
Allowance for loan losses: Collectively evaluated for impairment	56,320				56,320						81,898
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0						0
Allowance for loan losses: Total	68,509		97,613		68,509		97,613		70,366		95,656		102,391		123,115
Outstanding loan balances: Individually evaluated for impairment	104,308				104,308						112,320
Outstanding loan balances: Collectively evaluated for impairment	7,517,895				7,517,895						7,259,731
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0						0
Total loans	7,622,203				7,622,203						7,372,051
FDIC- Supported [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	0				0						0
Allowance for loan losses: Collectively evaluated for impairment	607				607						422
Allowance for loan losses: Purchased loans with evidence of credit deterioration	5,124				5,124						12,125
Allowance for loan losses: Total	5,731	[1]	12,850	[1]	5,731	[1]	12,850	[1]	5,915	[1]	12,547	[1]	20,917	[1]	23,472	[1]
Outstanding loan balances: Individually evaluated for impairment	1,051				1,051						1,149
Outstanding loan balances: Collectively evaluated for impairment	40,559				40,559						57,896
Outstanding loan balances: Purchased loans with evidence of credit deterioration	333,251				333,251						469,196
Total loans	374,861				374,861						528,241
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0		3,943		0		1,314
Impaired Financing Receivable, Interest Income, Accrual Method	0		0		0
Total loans	448,643				448,643						494,183
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	416,656		324,135		386,265		298,572
Impaired Financing Receivable, Interest Income, Accrual Method	2,020		1,388		5,404		4,124
Total loans	20,106,831				20,106,831						19,762,723
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	135,013		205,295		139,194		188,064
Impaired Financing Receivable, Interest Income, Accrual Method	623		1,133		2,754		2,780
Total loans	2,240,295				2,240,295						1,939,413
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	288,980		288,735		285,307		258,159
Impaired Financing Receivable, Interest Income, Accrual Method	1,969		1,723		5,571		5,806
Total loans	7,928,540				7,928,540						8,062,819
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	423,993		494,030		424,501		446,223
Impaired Financing Receivable, Interest Income, Accrual Method	2,592		2,856		8,325		8,586
Total loans	10,168,835				10,168,835						10,002,232
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	14,606		742		12,943		847
Impaired Financing Receivable, Interest Income, Accrual Method	120		3		262		6
Total loans	2,124,328				2,124,328						2,177,680
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	103,379		86,103		100,012		79,993
Impaired Financing Receivable, Interest Income, Accrual Method	457		431		1,171		1,162
Total loans	4,636,895				4,636,895						4,350,329
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	5,501		6,764		5,767		6,641
Impaired Financing Receivable, Interest Income, Accrual Method	49		43		141		128
Total loans	321,436				321,436						321,235
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0		287		0		128
Impaired Financing Receivable, Interest Income, Accrual Method	0		0		0		0
Total loans	331,966				331,966						306,428
Consumer Other Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1,751		1,972		1,784		2,320
Impaired Financing Receivable, Interest Income, Accrual Method	0		0		0		0
Total loans	207,578				207,578						216,379
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	125,237		95,868		120,506		89,929
Impaired Financing Receivable, Interest Income, Accrual Method	626		477		1,574		1,296
Total loans	7,622,203				7,622,203						7,372,051
Fdic Supported Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	363,293		94,890		404,826		102,709
Impaired Financing Receivable, Interest Income, Accrual Method	20,004	[2]	14,055	[2]	79,153	[2]	34,202	[2]
Total loans	$ 374,861				$ 374,861						$ 528,241

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

[2] The balance of interest income recognized results primarily from accretion of interest income on impaired FDIC-supported loans.