Financial Instruments (Schedule Of Derivatives And Hedged Items In Fair Value Hedging Relationships) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) on the Derivative Recognized in the Consolidated Statement of Income	$ 2,522
Amount of Gain or (Loss) on the Hedged Item Recognized in the Consolidated Statement of Income	(2,522)
Operating Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) on the Derivative Recognized in the Consolidated Statement of Income	2,997
Amount of Gain or (Loss) on the Hedged Item Recognized in the Consolidated Statement of Income	(2,997)
Purchased Gas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) on the Derivative Recognized in the Consolidated Statement of Income	(475)
Amount of Gain or (Loss) on the Hedged Item Recognized in the Consolidated Statement of Income	$ 475