Derivative Instruments and Hedging Activities (Details 2) (Borrowings [Member], Fair Value Hedging [Member], Other Income Expense [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Borrowings [Member] | Fair Value Hedging [Member] | Other Income Expense [Member]
Interest Rate Fair Value Hedges [Abstract]
Gain/(Loss) on the hedged fixed rate debt attributable to changes in the market interest rates	$ 577	$ 1,041	$ 1,732	$ 2,771