Fair Value (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 3,097
Total investment securities - available-for-sale	2,500,784	2,071,276
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	3,097
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
U.S. Treasury [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	11,841	65,769
U.S. Treasury [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	11,841
U.S. Treasury [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
U.S. Treasury [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
U.S. Government-Sponsored Entities And Agencies [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	517,325
U.S. Government-Sponsored Entities And Agencies [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
U.S. Government-Sponsored Entities And Agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	517,325
U.S. Government-Sponsored Entities And Agencies [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Mortgage-Backed Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	1,163,788	1,182,255
Mortgage-Backed Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Mortgage-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	1,163,788
Mortgage-Backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Non-agency Mortgage-Backed Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities		158,000
Total investment securities - available-for-sale	30,196
Non-agency Mortgage-Backed Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Non-agency Mortgage-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	30,196
Non-agency Mortgage-Backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
States And Political Subdivisions [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	577,324	402,844
States And Political Subdivisions [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
States And Political Subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	576,340
States And Political Subdivisions [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	984
Pooled Trust Preferred Securities Group 1 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	9,359	7,327
Pooled Trust Preferred Securities Group 1 [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Pooled Trust Preferred Securities Group 1 [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Pooled Trust Preferred Securities Group 1 [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	9,359
Other Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	190,951	153,996
Other Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	32,762
Other Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	158,189
Other Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Residential Loans Held For Sale [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	12,591
Residential Loans Held For Sale [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Residential Loans Held For Sale [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	12,591
Residential Loans Held For Sale [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	0
Derivative Assets [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	36,512
Derivative Assets [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	0
Derivative Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	36,512
Derivative Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	0
Derivative Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	30,010
Derivative Liabilities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	0
Derivative Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	30,010
Derivative Liabilities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	$ 0