Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	$ 37,924,207		$ 37,046,712
30-89 days past due	141,360		269,740
90+ days past due	207,163		348,795
Total past due	348,523		618,535
Total loans	38,272,730		37,665,247
Accruing loans 90+ days past due	31,848		61,763
Nonaccrual loans that are current	250,974	[1]	288,728	[1]
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	20,106,831		19,762,723
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	19,932,181		19,487,495
30-89 days past due	68,129		130,174
90+ days past due	106,521		145,054
Total past due	174,650		275,228
Total loans	20,106,831		19,762,723
Accruing loans 90+ days past due	5,386		5,835
Nonaccrual loans that are current	151,930	[1]	142,458	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	10,168,835		10,002,232
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	7,622,203		7,372,051
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,566,819		7,283,781
30-89 days past due	22,520		36,290
90+ days past due	32,864		51,980
Total past due	55,384		88,270
Total loans	7,622,203		7,372,051
Accruing loans 90+ days past due	1,651		2,935
Nonaccrual loans that are current	34,724	[1]	34,287	[1]
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	11,820,258		11,124,639
30-89 days past due	28,268		73,555
90+ days past due	55,951		58,751
Total past due	84,219		132,306
Total loans	11,904,477		11,256,945
Accruing loans 90+ days past due	2,280		4,013
Nonaccrual loans that are current	44,546	[1]	32,389	[1]
Leasing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	374,200		421,590
30-89 days past due	323		115
90+ days past due	602		808
Total past due	925		923
Total loans	375,125		422,513
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	0	[1]	0	[1]
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,289,080		7,447,083
30-89 days past due	39,538		56,504
90+ days past due	49,968		85,495
Total past due	89,506		141,999
Total loans	7,378,586		7,589,082
Accruing loans 90+ days past due	3,106		1,822
Nonaccrual loans that are current	97,378	[1]	100,835	[1]
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	448,643		494,183
30-89 days past due	0		0
90+ days past due	0		0
Total past due	0		0
Total loans	448,643		494,183
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	10,006	[1]	9,234	[1]
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,200,392		1,836,284
30-89 days past due	21,609		66,139
90+ days past due	18,294		36,990
Total past due	39,903		103,129
Total loans	2,240,295		1,939,413
Accruing loans 90+ days past due	0		853
Nonaccrual loans that are current	28,140	[1]	50,044	[1]
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,885,730		7,984,819
30-89 days past due	17,940		24,730
90+ days past due	24,870		53,270
Total past due	42,810		78,000
Total loans	7,928,540		8,062,819
Accruing loans 90+ days past due	2,361		107
Nonaccrual loans that are current	33,780	[1]	54,546	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	10,086,122		9,821,103
30-89 days past due	39,549		90,869
90+ days past due	43,164		90,260
Total past due	82,713		181,129
Total loans	10,168,835		10,002,232
Accruing loans 90+ days past due	2,361		960
Nonaccrual loans that are current	61,920	[1]	104,590	[1]
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,116,048		2,169,722
30-89 days past due	4,357		4,036
90+ days past due	3,923		3,922
Total past due	8,280		7,958
Total loans	2,124,328		2,177,680
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	3,226	[1]	8,846	[1]
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	4,598,613		4,282,611
30-89 days past due	13,816		24,060
90+ days past due	24,466		43,658
Total past due	38,282		67,718
Total loans	4,636,895		4,350,329
Accruing loans 90+ days past due	551		1,423
Nonaccrual loans that are current	28,850	[1]	21,945	[1]
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	317,305		314,931
30-89 days past due	1,574		4,344
90+ days past due	2,557		1,960
Total past due	4,131		6,304
Total loans	321,436		321,235
Accruing loans 90+ days past due	368		395
Nonaccrual loans that are current	1,738	[1]	2,500	[1]
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	329,055		302,587
30-89 days past due	1,951		2,439
90+ days past due	960		1,402
Total past due	2,911		3,841
Total loans	331,966		306,428
Accruing loans 90+ days past due	669		1,010
Nonaccrual loans that are current	840	[1]	721	[1]
Consumer Other Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	205,798		213,930
30-89 days past due	822		1,411
90+ days past due	958		1,038
Total past due	1,780		2,449
Total loans	207,578		216,379
Accruing loans 90+ days past due	63		107
Nonaccrual loans that are current	70	[1]	275	[1]
Fdic Supported Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	339,085		454,333
30-89 days past due	11,162		12,407
90+ days past due	24,614		61,501
Total past due	35,776		73,908
Total loans	374,861		528,241
Accruing loans 90+ days past due	22,450		52,033
Nonaccrual loans that are current	$ 2,400	[1]	$ 7,393	[1]

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