Fair Value (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 2,918	$ 2,816
Total investment securities - available-for-sale	2,208,262	2,071,276	2,202,855
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	2,918	2,816
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
U.S. Treasury [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	15,598	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	15,598	65,769
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	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	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	347,289	173,185
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	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	347,289	173,185
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	0
Mortgage-Backed Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	1,140,942	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	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	1,140,942	1,182,255
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	0
Non-agency Mortgage-Backed Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	73,747	85,900
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	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	73,747	85,900
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	0
States And Political Subdivisions [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	462,065	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	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	461,076	401,538
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	989	1,306
Pooled Trust Preferred Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	8,460	7,327
Pooled Trust Preferred 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	0
Pooled Trust Preferred 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	0	0
Pooled Trust Preferred 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	8,460	7,327
Other Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities - available-for-sale	160,161	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	0	0
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	160,161	153,996
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	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	4,366	4,528
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	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	4,366	4,528
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	0
Derivative Assets [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	40,953	44,415
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	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	40,953	44,415
Derivative Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets	0	0
Derivative Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	33,601	37,332
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	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	33,601	37,332
Derivative Liabilities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liabilities	$ 0	$ 0