Goodwill And Other Intangible Assets (Schedule Of Gross Carrying Amount And Accumulated Amortization Of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 73,711	$ 73,197
Accumulated Amortization and Impairment	(43,506)	(39,573)
Net Carrying Amount	30,205	33,624
Core Deposit Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	39,265	39,265
Accumulated Amortization and Impairment	(23,375)	(20,815)
Net Carrying Amount	15,890	18,450
Customer Business Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,411	25,897
Accumulated Amortization and Impairment	(17,221)	(16,312)
Net Carrying Amount	9,190	9,585
Trust Customer Relationship Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,622	3,622
Accumulated Amortization and Impairment	(737)	(474)
Net Carrying Amount	2,885	3,148
Customer Loan Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,413	4,413
Accumulated Amortization and Impairment	(2,173)	(1,972)
Net Carrying Amount	$ 2,240	$ 2,441