Goodwill And Other Intangible Assets (Schedule Of Gross Carrying Amount And Accumulated Amortization Of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 76,735		$ 73,197
Accumulated Amortization and Impairment	(47,515)		(39,573)
Net Carrying Amount	29,220	29,220	33,624
Core Deposit Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	40,559		39,265
Accumulated Amortization and Impairment	(25,908)		(20,815)
Net Carrying Amount	14,651		18,450
Customer Business Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,411		25,897
Accumulated Amortization and Impairment	(18,153)		(16,312)
Net Carrying Amount	8,258		9,585
Customer Trust Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,352		3,622
Accumulated Amortization and Impairment	(1,080)		(474)
Net Carrying Amount	4,272		3,148
Customer Loan Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,413		4,413
Accumulated Amortization and Impairment	(2,374)		(1,972)
Net Carrying Amount	$ 2,039		$ 2,441