Regulatory Matters (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Regulatory Matters [Abstract]
Elimination Of Other Post Retirement Regulatory Liability	$ 21,700	$ (21,672)	$ 0	$ 0