Fair Value Disclosures (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Thousands	Sep. 30, 2011		Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	$ 2,715,035	[1]	$ 2,426,291	[1]
Total Liabilities	76,085	[2]	48,560	[2]
U.S. Government Agencies [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	0		0
Other Equity Securities [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	1,574		2,446
Designated As Hedging Instruments [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Liabilities	0	[2]	0	[2]
Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	1,574	[1]	2,446	[1]
Total Liabilities	0	[2]	0	[2]
U.S. Government Agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	235,757		268,175
Obligations Of States And Political Subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	412,934		396,660
Agency Residential Mortgage-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	1,691,587		1,323,569
Non-Agency Residential Mortgage-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	74,767		116,811
Other Structured Financial Products [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	0		0
Other Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	50,672		41,000
Other Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	19,304		18,266
Designated As Hedging Instruments [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Assets	40	[1]	181	[1]
Derivatives, Liabilities	53,802	[2]	31,793	[2]
Not Designated As Hedges [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Assets	23,708	[1]	17,167	[1]
Derivatives, Liabilities	22,283	[2]	16,767	[2]
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	2,697,291	[1]	2,407,961	[1]
Total Liabilities	76,085	[2]	48,560	[2]
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	65,290		104,842
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities Of FHLB [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	73,007		71,065
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities Of FRB [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	50,225		50,225
U.S. Government Agencies [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	0		0
Other Structured Financial Products [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	12,740		12,503
Other Equity Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	3,430		3,381
Designated As Hedging Instruments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Liabilities	0	[2]	0	[2]
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	16,170	[1]	15,884	[1]
Total Liabilities	0	[2]	0	[2]
Designated As Hedging Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Assets	40	[1]	181	[1]
Derivatives, Liabilities	53,802	[2]	31,793	[2]
Not Designated As Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Assets	23,708	[1]	17,167	[1]
Derivatives, Liabilities	22,283	[2]	16,767	[2]
U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	235,757		268,175
Obligations Of States And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	412,934		396,660
Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	1,691,587		1,323,569
Non-Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	74,767		116,811
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	65,290		104,842
Other Structured Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	12,740		12,503
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	50,672		41,000
Equity Securities Of FHLB [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	73,007		71,065
Equity Securities Of FRB [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	50,225		50,225
Other Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities:	$ 24,308		$ 24,093

[1] Included in Other assets

[2] Included in Other liabilities