Loans And Allowance For Credit Losses (Outstanding Loan Balances (Accruing And Nonaccruing) Categorized By These Credit Quality Indicators) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans held for sale	$ 201,590	$ 206,286
Commercial and industrial	10,393,496	9,167,001
Leasing	422,431	410,174
Owner occupied	8,165,993	8,217,363
Municipal	442,060	438,985
Total commercial	19,423,980	18,233,523
Construction and land development	2,276,114	3,499,103
Term	7,906,179	7,649,494
Total commercial real estate	10,182,293	11,148,597
Home equity credit line	2,184,515	2,141,740
1-4 family residential	3,915,008	3,499,149
Construction and other consumer real estate	306,764	343,257
Bankcard and other revolving plans	290,920	296,936
Consumer Other	223,181	233,193
Total consumer loans	6,920,388	6,514,275
FDIC-supported loans	751,091	971,377
Total loans	37,277,752	36,867,772
Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans held for sale	182,626	206,286
Total loans	34,106,084	31,992,010
Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	919,598	1,187,976
Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans held for sale	18,964
Total loans	2,225,424	3,641,031
Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	26,646	46,755
Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans held for sale	201,590	206,286
Total loans	37,277,752	36,867,772
Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,049,958	1,440,341
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	126,468	224,499
Total loans	19,423,980	18,233,523
Commercial [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	9,670,781	8,234,515
Leasing	405,433	395,081
Owner occupied	7,488,644	7,358,189
Municipal	426,626	436,983
Total commercial	17,991,484	16,424,768
Commercial [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	271,845	254,369
Leasing	5,878	1,170
Owner occupied	184,821	147,562
Municipal	15,434
Total commercial	477,978	403,101
Commercial [Member] | Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	442,139	658,400
Leasing	11,120	13,923
Owner occupied	486,584	705,128
Municipal		2,002
Total commercial	939,843	1,379,453
Commercial [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	8,731	19,717
Owner occupied	5,944	6,484
Total commercial	14,675	26,201
Commercial [Member] | Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial	10,393,496	9,167,001
Leasing	422,431	410,174
Owner occupied	8,165,993	8,217,363
Municipal	442,060	438,985
Total commercial	19,423,980	18,233,523
Commercial [Member] | Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total commercial	627,825	761,107
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	10,182,293	11,148,597
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Term	7,266,423	6,768,022
Total commercial real estate	8,925,369	8,689,132
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Term	196,377	252,814
Total commercial real estate	383,700	723,245
Commercial Real Estate [Member] | Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Term	437,390	624,196
Total commercial real estate	863,542	1,717,968
Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Term	5,989	4,462
Total commercial real estate	9,682	18,252
Commercial Real Estate [Member] | Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Term	7,906,179	7,649,494
Total commercial real estate	10,182,293	11,148,597
Commercial Real Estate [Member] | Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total commercial real estate	275,546	487,235
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	18,376	14,047
1-4 family residential	90,857	124,470
Construction and other consumer real estate	12,096	23,719
Bankcard and other revolving plans	346	958
Total loans	6,920,388	6,514,275
Consumer [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	2,133,277	2,098,365
1-4 family residential	3,782,750	3,313,875
Construction and other consumer real estate	275,603	310,209
Bankcard and other revolving plans	278,669	282,353
Consumer Other	218,755	226,832
Total consumer loans	6,689,054	6,231,634
Consumer [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	106	855
1-4 family residential	5,736	7,274
Construction and other consumer real estate	12,206	3,424
Bankcard and other revolving plans	3,832	4,535
Consumer Other	163	111
Total consumer loans	22,043	16,199
Consumer [Member] | Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	51,089	42,349
1-4 family residential	126,277	177,963
Construction and other consumer real estate	16,967	29,176
Bankcard and other revolving plans	8,419	10,040
Consumer Other	4,256	6,038
Total consumer loans	207,008	265,566
Consumer [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	43	171
1-4 family residential	245	37
Construction and other consumer real estate	1,988	448
Bankcard and other revolving plans		8
Consumer Other	7	212
Total consumer loans	2,283	876
Consumer [Member] | Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Home equity credit line	2,184,515	2,141,740
1-4 family residential	3,915,008	3,499,149
Construction and other consumer real estate	306,764	343,257
Bankcard and other revolving plans	290,920	296,936
Consumer Other	223,181	233,193
Total consumer loans	6,920,388	6,514,275
Consumer [Member] | Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total consumer loans	123,115	154,326
Construction And Land Development [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development	1,658,946	1,921,110
Construction And Land Development [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development	187,323	470,431
Construction And Land Development [Member] | Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development	426,152	1,093,772
Construction And Land Development [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development	3,693	13,790
Construction And Land Development [Member] | Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development	2,276,114	3,499,103
FDIC Supported Loans [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	500,177	646,476
FDIC Supported Loans [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	35,877	45,431
FDIC Supported Loans [Member] | Sub-Standard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	215,031	278,044
FDIC Supported Loans [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	6	1,426
FDIC Supported Loans [Member] | Total Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	751,091	971,377
FDIC Supported Loans [Member] | Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
FDIC-supported loans	$ 23,472	$ 37,673