Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Receivable Held-for-sale, Net	$ 171,328		$ 251,651
Current	38,711,947		37,046,712
30-89 days past due	145,849		269,740
90+ days past due	185,569		348,795
Total past due	331,418		618,535
Total loans	39,043,365		37,665,247
Accruing loans 90+ days past due	40,348		61,763
Nonaccrual loans that are current	232,055	[1]	288,728	[1]
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current			19,487,495
30-89 days past due			130,174
90+ days past due			145,054
Total past due			275,228
Total loans	20,755,625		19,762,723
Accruing loans 90+ days past due			5,835
Nonaccrual loans that are current			142,458	[1]
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	20,573,298
30-89 days past due	89,009
90+ days past due	93,318
Total past due	182,327
Total loans	20,755,625
Accruing loans 90+ days past due	2,635
Nonaccrual loans that are current	136,223
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current			9,821,103
30-89 days past due			90,869
90+ days past due			90,260
Total past due			181,129
Total loans	10,188,658		10,002,232
Accruing loans 90+ days past due			960
Nonaccrual loans that are current			104,590	[1]
Home Equity Credit Line [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,122,549		2,169,722
30-89 days past due	8,001		4,036
90+ days past due	2,570		3,922
Total past due	10,571		7,958
Total loans	2,133,120		2,177,680
Accruing loans 90+ days past due	98		0
Nonaccrual loans that are current	2,868	[1]	8,846	[1]
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current			7,283,781
30-89 days past due			36,290
90+ days past due			51,980
Total past due			88,270
Total loans	7,748,811		7,372,051
Accruing loans 90+ days past due			2,935
Nonaccrual loans that are current			34,287	[1]
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	12,387,546		11,124,639
30-89 days past due	48,811		73,555
90+ days past due	44,726		58,751
Total past due	93,537		132,306
Total loans	12,481,083		11,256,945
Accruing loans 90+ days past due	1,855		4,013
Nonaccrual loans that are current	52,412	[1]	32,389	[1]
Leasing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	387,526		421,590
30-89 days past due	173		115
90+ days past due	230		808
Total past due	403		923
Total loans	387,929		422,513
Accruing loans 90+ days past due	36		0
Nonaccrual loans that are current	563	[1]	0	[1]
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,357,618		7,447,083
30-89 days past due	36,718		56,504
90+ days past due	42,859		85,495
Total past due	79,577		141,999
Total loans	7,437,195		7,589,082
Accruing loans 90+ days past due	744		1,822
Nonaccrual loans that are current	82,072	[1]	100,835	[1]
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	440,608		494,183
30-89 days past due	3,307		0
90+ days past due	5,503		0
Total past due	8,810		0
Total loans	449,418		494,183
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	1,176	[1]	9,234	[1]
Construction And Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,162,018		1,836,284
30-89 days past due	8,967		66,139
90+ days past due	11,836		36,990
Total past due	20,803		103,129
Total loans	2,182,821		1,939,413
Accruing loans 90+ days past due	23		853
Nonaccrual loans that are current	17,311	[1]	50,044	[1]
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,971,327		7,984,819
30-89 days past due	15,362		24,730
90+ days past due	19,148		53,270
Total past due	34,510		78,000
Total loans	8,005,837		8,062,819
Accruing loans 90+ days past due	5,580		107
Nonaccrual loans that are current	42,624	[1]	54,546	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	10,133,345
30-89 days past due	24,329
90+ days past due	30,984
Total past due	55,313
Total loans	10,188,658
Accruing loans 90+ days past due	5,603
Nonaccrual loans that are current	59,935
1-4 Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	4,704,852		4,282,611
30-89 days past due	8,526		24,060
90+ days past due	23,287		43,658
Total past due	31,813		67,718
Total loans	4,736,665		4,350,329
Accruing loans 90+ days past due	667		1,423
Nonaccrual loans that are current	27,592	[1]	21,945	[1]
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	322,807		314,931
30-89 days past due	1,038		4,344
90+ days past due	1,077		1,960
Total past due	2,115		6,304
Total loans	324,922		321,235
Accruing loans 90+ days past due	0		395
Nonaccrual loans that are current	2,232	[1]	2,500	[1]
Bankcard And Other Revolving Plans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	353,060		302,587
30-89 days past due	2,093		2,439
90+ days past due	1,087		1,402
Total past due	3,180		3,841
Total loans	356,240		306,428
Accruing loans 90+ days past due	900		1,010
Nonaccrual loans that are current	1,105	[1]	721	[1]
Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	196,327		213,930
30-89 days past due	827		1,411
90+ days past due	710		1,038
Total past due	1,537		2,449
Total loans	197,864		216,379
Accruing loans 90+ days past due	54		107
Nonaccrual loans that are current	125	[1]	275	[1]
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,699,595
30-89 days past due	20,485
90+ days past due	28,731
Total past due	49,216
Total loans	7,748,811
Accruing loans 90+ days past due	1,719
Nonaccrual loans that are current	33,922
FDIC-Supported Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	305,709		454,333
30-89 days past due	12,026		12,407
90+ days past due	32,536		61,501
Total past due	44,562		73,908
Total loans	350,271		528,241
Accruing loans 90+ days past due	30,391		52,033
Nonaccrual loans that are current	1,975	[1]	7,393	[1]
Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 700,374		$ 696,548

[1] Represents nonaccrual loans not past due more than 30 days; however, full payment of principal and interest is still not expected.