Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	$ 38,833,278		$ 38,711,947
30-89 days past due	162,626		145,849
90+ days past due	202,232		185,569
Total past due	364,858		331,418
Total loans	39,198,136		39,043,365
Accruing loans 90+ days past due	38,191		40,348
Nonaccrual loans that are current	189,404	[1]	232,055	[1]
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	20,731,093		20,755,625
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	20,529,162		20,573,298
30-89 days past due	98,083		89,009
90+ days past due	103,848		93,318
Total past due	201,931		182,327
Total loans	20,731,093		20,755,625
Accruing loans 90+ days past due	956		2,635
Nonaccrual loans that are current	118,208	[1]	136,223	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	10,344,268		10,188,658
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	7,837,462		7,748,811
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,786,089		7,699,595
30-89 days past due	23,038		20,485
90+ days past due	28,335		28,731
Total past due	51,373		49,216
Total loans	7,837,462		7,748,811
Accruing loans 90+ days past due	1,713		1,719
Nonaccrual loans that are current	31,000	[1]	33,922	[1]
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	12,403,866		12,387,546
30-89 days past due	53,684		48,811
90+ days past due	54,080		44,726
Total past due	107,764		93,537
Total loans	12,511,630		12,481,083
Accruing loans 90+ days past due	826		1,855
Nonaccrual loans that are current	45,137	[1]	52,412	[1]
Leasing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	389,201		387,526
30-89 days past due	181		173
90+ days past due	194		230
Total past due	375		403
Total loans	389,576		387,929
Accruing loans 90+ days past due	0		36
Nonaccrual loans that are current	490	[1]	563	[1]
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	7,262,832		7,357,618
30-89 days past due	44,218		36,718
90+ days past due	40,763		42,859
Total past due	84,981		79,577
Total loans	7,347,813		7,437,195
Accruing loans 90+ days past due	130		744
Nonaccrual loans that are current	71,445	[1]	82,072	[1]
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	473,263		440,608
30-89 days past due	0		3,307
90+ days past due	8,811		5,503
Total past due	8,811		8,810
Total loans	482,074		449,418
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	1,136	[1]	1,176	[1]
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,246,891		2,162,018
30-89 days past due	5,518		8,967
90+ days past due	11,511		11,836
Total past due	17,029		20,803
Total loans	2,263,920		2,182,821
Accruing loans 90+ days past due	0		23
Nonaccrual loans that are current	16,934	[1]	17,311	[1]
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	8,023,737		7,971,327
30-89 days past due	31,597		15,362
90+ days past due	25,014		19,148
Total past due	56,611		34,510
Total loans	8,080,348		8,005,837
Accruing loans 90+ days past due	3,992		5,580
Nonaccrual loans that are current	21,690	[1]	42,624	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	10,270,628		10,133,345
30-89 days past due	37,115		24,329
90+ days past due	36,525		30,984
Total past due	73,640		55,313
Total loans	10,344,268		10,188,658
Accruing loans 90+ days past due	3,992		5,603
Nonaccrual loans that are current	38,624	[1]	59,935	[1]
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	2,151,938		2,122,549
30-89 days past due	6,305		8,001
90+ days past due	7,042		2,570
Total past due	13,347		10,571
Total loans	2,165,285		2,133,120
Accruing loans 90+ days past due	0		98
Nonaccrual loans that are current	2,145	[1]	2,868	[1]
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	4,765,571		4,704,852
30-89 days past due	11,351		8,526
90+ days past due	18,562		23,287
Total past due	29,913		31,813
Total loans	4,795,484		4,736,665
Accruing loans 90+ days past due	702		667
Nonaccrual loans that are current	25,889	[1]	27,592	[1]
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	326,297		322,807
30-89 days past due	3,035		1,038
90+ days past due	883		1,077
Total past due	3,918		2,115
Total loans	330,215		324,922
Accruing loans 90+ days past due	0		0
Nonaccrual loans that are current	2,100	[1]	2,232	[1]
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	357,596		353,060
30-89 days past due	1,722		2,093
90+ days past due	1,071		1,087
Total past due	2,793		3,180
Total loans	360,389		356,240
Accruing loans 90+ days past due	1,008		900
Nonaccrual loans that are current	739	[1]	1,105	[1]
Consumer Other Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	184,687		196,327
30-89 days past due	625		827
90+ days past due	777		710
Total past due	1,402		1,537
Total loans	186,089		197,864
Accruing loans 90+ days past due	3		54
Nonaccrual loans that are current	127	[1]	125	[1]
Fdic Supported Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	247,399		305,709
30-89 days past due	4,390		12,026
90+ days past due	33,524		32,536
Total past due	37,914		44,562
Total loans	285,313		350,271
Accruing loans 90+ days past due	31,530		30,391
Nonaccrual loans that are current	$ 1,572	[1]	$ 1,975	[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.