Significant Accounting Policies Textuals (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Gas Utility [Member]	Sep. 30, 2012 Gas Utility [Member]	Sep. 30, 2011 Gas Utility [Member]	Sep. 30, 2013 Electric Utility [Member]	Sep. 30, 2012 Electric Utility [Member]	Sep. 30, 2011 Electric Utility [Member]
Accounting Policies [Abstract]
Error in the classification of deferred income tax assets, amount	$ 27,006
Property, Plant and Equipment [Line Items]
Depreciation expense as percentage of related average depreciable base		2.30%	2.20%	2.30%	2.40%	2.40%	2.60%