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
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013		Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 907,227		$ 1,363,323
Impaired Financing Receivable, Interest Income, Accrual Method	26,545		29,802
Allowance for loan losses: Individually evaluated for impairment	(59,285)				(62,499)
Allowance for loan losses: Collectively evaluated for impairment	673,417				677,266
Allowance for loan losses: Purchased loans with evidence of credit deterioration	4,251				6,526
Allowance for loan losses: Total	736,953		841,781		746,291		896,087
Outstanding loan balances: Individually evaluated for impairment	671,671				681,280
Outstanding loan balances: Collectively evaluated for impairment	38,277,498				38,051,001
Outstanding loan balances: Purchased loans with evidence of credit deterioration	248,967				311,084
Total loans	39,198,136				39,043,365
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	175,155		177,745
Impaired Financing Receivable, Interest Income, Accrual Method	1,024		856
Total loans	12,511,630				12,481,083
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	137,175		182,825
Impaired Financing Receivable, Interest Income, Accrual Method	752		806
Total loans	7,347,813				7,437,195
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(41,739)				(39,288)
Allowance for loan losses: Collectively evaluated for impairment	432,809				425,857
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0
Allowance for loan losses: Total	474,548		496,930		465,145		510,908
Outstanding loan balances: Individually evaluated for impairment	329,389				315,604
Outstanding loan balances: Collectively evaluated for impairment	20,401,704				20,440,021
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0
Total loans	20,731,093				20,755,625
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(7,409)				(12,510)
Allowance for loan losses: Collectively evaluated for impairment	199,137				200,853
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0
Allowance for loan losses: Total	206,546		256,421		213,363		276,976
Outstanding loan balances: Individually evaluated for impairment	240,384				262,907
Outstanding loan balances: Collectively evaluated for impairment	10,103,884				9,925,751
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0
Total loans	10,344,268				10,188,658
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(10,137)				(10,701)
Allowance for loan losses: Collectively evaluated for impairment	40,943				50,164
Allowance for loan losses: Purchased loans with evidence of credit deterioration	0				0
Allowance for loan losses: Total	51,080		84,622		60,865		95,656
Outstanding loan balances: Individually evaluated for impairment	100,680				101,545
Outstanding loan balances: Collectively evaluated for impairment	7,736,782				7,647,266
Outstanding loan balances: Purchased loans with evidence of credit deterioration	0				0
Total loans	7,837,462				7,748,811
FDIC- Supported [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	0				0
Allowance for loan losses: Collectively evaluated for impairment	528				392
Allowance for loan losses: Purchased loans with evidence of credit deterioration	4,251				6,526
Allowance for loan losses: Total	4,779	[1]	3,808	[1]	6,918	[1]	12,547	[1]
Outstanding loan balances: Individually evaluated for impairment	1,218				1,224
Outstanding loan balances: Collectively evaluated for impairment	35,128				37,963
Outstanding loan balances: Purchased loans with evidence of credit deterioration	248,967				311,084
Total loans	285,313				350,271
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	482,074				449,418
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	312,330		360,570
Impaired Financing Receivable, Interest Income, Accrual Method	1,776		1,662
Total loans	20,731,093				20,755,625
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	62,548		147,225
Impaired Financing Receivable, Interest Income, Accrual Method	552		664
Total loans	2,263,920				2,182,821
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	149,425		289,103
Impaired Financing Receivable, Interest Income, Accrual Method	1,294		1,836
Total loans	8,080,348				8,005,837
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	211,973		436,328
Impaired Financing Receivable, Interest Income, Accrual Method	1,846		2,500
Total loans	10,344,268				10,188,658
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	14,952		11,455
Impaired Financing Receivable, Interest Income, Accrual Method	135		59
Total loans	2,165,285				2,133,120
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	80,154		99,191
Impaired Financing Receivable, Interest Income, Accrual Method	448		382
Total loans	4,795,484				4,736,665
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	3,332		6,122
Impaired Financing Receivable, Interest Income, Accrual Method	35		46
Total loans	330,215				324,922
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	360,389				356,240
Consumer Other Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	704		1,816
Impaired Financing Receivable, Interest Income, Accrual Method	0		0
Total loans	186,089				197,864
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	99,142		118,584
Impaired Financing Receivable, Interest Income, Accrual Method	618		487
Total loans	7,837,462				7,748,811
Fdic Supported Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	283,782		447,841
Impaired Financing Receivable, Interest Income, Accrual Method	22,305	[2]	25,153	[2]
Total loans	$ 285,313				$ 350,271

[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.