Loans And Allowance For Credit Losses (Summary Of Selected Information On TDRs That Includes Recorded Investment On An Accruing And Nonaccruing Basis By Loan Class And Modification Type) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 882		$ 2,336	$ 2,850		$ 10,460	$ 178,800	$ 164,600
Recorded investment resulting from the following modification types	551,366			551,366					622,502
1-4 family residential	4,636,895			4,636,895					4,350,329
Construction and other consumer real estate	321,436			321,436					321,235
Commercial and industrial	11,904,477			11,904,477					11,256,945
Home equity credit line	2,124,328			2,124,328					2,177,680
Bankcard and other revolving plans	331,966			331,966					306,428
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	11,904,477			11,904,477					11,256,945
Consumer [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	4,636,895			4,636,895					4,350,329
Construction and other consumer real estate	321,436			321,436					321,235
Home equity credit line	2,124,328			2,124,328					2,177,680
Bankcard and other revolving plans	331,966			331,966					306,428
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	660		107	660		1,441
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0		0	511		5,405
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	660		107	1,171		6,846
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0		2,229	0		2,525
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0		0	0		0
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0		2,229	0		2,525
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	222		0	307		0
One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0		0	1,372		1,089
Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	222		0	1,679		1,089
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	72,259			72,259
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	60,855			60,855
Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	51,668			51,668
Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	136,445			136,445
Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	10,325			10,325
Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	50,546			50,546
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	2,695			2,695
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	26,569			26,569
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	33,590			33,590
Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	59,171			59,171
Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	14,636			14,636
Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	1,927			1,927
Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	28,455			28,455
Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	1,965			1,965
Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	260			260					287
Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	87,012			87,012					91,884
Interest Rate Below Market [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	355			355
Interest Rate Below Market [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	22,121			22,121
Interest Rate Below Market [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	2,062			2,062
Interest Rate Below Market [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	34,482			34,482
Interest Rate Below Market [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	743			743
Interest Rate Below Market [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	2,649			2,649
Interest Rate Below Market [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	133			133
Interest Rate Below Market [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	2,609			2,609
Interest Rate Below Market [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	3,096			3,096
Interest Rate Below Market [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	11,822			11,822
Interest Rate Below Market [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	2,480			2,480
Interest Rate Below Market [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	0			0
Interest Rate Below Market [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	4,455			4,455
Interest Rate Below Market [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	5			5
Interest Rate Below Market [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	0			0					0
Maturity Or Term Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	58,808			58,808					51,214
Maturity Or Term Extension [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	15,794			15,794
Maturity Or Term Extension [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	4,768			4,768
Maturity Or Term Extension [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	11,688			11,688
Maturity Or Term Extension [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	9,516			9,516
Maturity Or Term Extension [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Maturity Or Term Extension [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	1,294			1,294
Maturity Or Term Extension [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	963			963
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	8,958			8,958
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	1,471			1,471
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	1,750			1,750
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	0			0
Maturity Or Term Extension [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	1,420			1,420
Maturity Or Term Extension [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	926			926
Maturity Or Term Extension [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	260			260					287
Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	27,612			27,612					29,033
Principal Forgiveness [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	0			0
Principal Forgiveness [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	994			994
Principal Forgiveness [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Principal Forgiveness [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	5,331			5,331
Principal Forgiveness [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	8,922			8,922
Principal Forgiveness [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	7,861			7,861
Principal Forgiveness [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	0			0
Principal Forgiveness [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	68			68
Principal Forgiveness [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	1,074			1,074
Principal Forgiveness [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Principal Forgiveness [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Principal Forgiveness [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	1,575			1,575
Principal Forgiveness [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	1,787			1,787
Principal Forgiveness [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	0			0
Principal Forgiveness [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	0			0					0
Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	23,380			23,380					19,609
Payment Deferral [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	6,856			6,856
Payment Deferral [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	2,961			2,961
Payment Deferral [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	1,120			1,120
Payment Deferral [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	5,766			5,766
Payment Deferral [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Payment Deferral [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	647			647
Payment Deferral [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	0			0
Payment Deferral [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	156			156
Payment Deferral [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	3,823			3,823
Payment Deferral [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	0			0
Payment Deferral [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	2,051			2,051
Payment Deferral [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	0			0
Payment Deferral [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	0			0
Payment Deferral [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	0			0
Payment Deferral [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	0			0					0
Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	83,785	[1]		83,785	[1]				94,645	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	14,326	[1]		14,326	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	10,145	[1]		10,145	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	8,836	[1]		8,836	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	22,405	[1]		22,405	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	325	[1]		325	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	4,482	[1]		4,482	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	144	[1]		144	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	1,362	[1]		1,362	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	11,182	[1]		11,182	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	5,591	[1]		5,591	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	325	[1]		325	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	222	[1]		222	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	4,440	[1]		4,440	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	0	[1]		0	[1]
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	0	[1]		0	[1]				0	[1]
Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	270,769	[2]		270,769	[2]				336,117	[2]
Multiple Modification Types [Member] | Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	34,928	[2]		34,928	[2]
Multiple Modification Types [Member] | Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	19,866	[2]		19,866	[2]
Multiple Modification Types [Member] | Accruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	27,962	[2]		27,962	[2]
Multiple Modification Types [Member] | Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	58,945	[2]		58,945	[2]
Multiple Modification Types [Member] | Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	335	[2]		335	[2]
Multiple Modification Types [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	33,613	[2]		33,613	[2]
Multiple Modification Types [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	1,455	[2]		1,455	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	13,416	[2]		13,416	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	12,944	[2]		12,944	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	40,008	[2]		40,008	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	9,780	[2]		9,780	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	130	[2]		130	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	16,353	[2]		16,353	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	1,034	[2]		1,034	[2]
Multiple Modification Types [Member] | Nonaccruing [Member] | ERROR in label resolution.
Financing Receivable, Modifications [Line Items]
Bankcard and other revolving plans	$ 0	[2]		$ 0	[2]				$ 0	[2]

[1] Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc.

[2] Includes TDRs that resulted from a combination of any of the previous modification types.