Derivatives and Hedging Activities (Schedule of Fair Value Derivative Instruments) (Details) (Derivatives Not Designated as Hedging Instruments [Member], Interest Rate Contracts [Member], USD $) In Thousands	Sep. 30, 2011	Sep. 30, 2010
Other Assets [Member]
Fair value of asset derivative instruments	$ 16,463	$ 13,623
Other Liabilities [Member]
Fair value of liability derivative instruments	$ 16,463	$ 13,623