Regulatory Assets and Liabilities and Regulatory Matters Textual (Details) (USD $) In Thousands, unless otherwise specified										0 Months Ended
	Jul. 31, 2013	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Deferral Fuel and Power [Member]	Sep. 30, 2012 Deferral Fuel and Power [Member]	Jun. 30, 2012 Deferral Fuel and Power [Member]	Jun. 30, 2013 Electric Utility Electric Supply Contracts [Member]	Sep. 30, 2012 Electric Utility Electric Supply Contracts [Member]	Jun. 30, 2012 Electric Utility Electric Supply Contracts [Member]	Oct. 03, 2012 Damage from Natural Gas Explosion [Member] Allentown, Pennsylvania Natural Gas Explosion [Member]	Feb. 09, 2011 Damage from Natural Gas Explosion [Member] Allentown, Pennsylvania Natural Gas Explosion [Member] Persons	Jun. 30, 2013 Allentown Incident [Member]	Jun. 30, 2013 Revised Penalty [Member] Allentown Incident [Member]
Regulatory Assets [Line Items]
GasUtilityUnrealizedGainOrLossOnDerivativeFinancialInstrumentsContracts				$ (1,352)	$ 5,303	$ 280
Site Contingency, Accelerated Time Frame Replacing Remainder of Cast-Iron Mains										14 years
Fair value of electric utility electricity supply contracts		(22,950)	(42,473)				(6,060)	(9,207)	(13,095)
Deaths from natural gas explosion (in persons)											5
Penalty Assessed												386	500
Loss Contingency, Agreement Permitted To Retain Current Timeframe for Replacing The Remainder of Their Bare Steel Mains										30 years
Net Book Value of The Pipeline	$ 2,650