Retirement Plan And Other Post-Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 2,997		$ 3,961
Interest Cost	10,893		9,124
Expected Return on Plan Assets	(14,993)		(14,336)
Amortization of Prior Service Cost (Credit)	52		60
Amortization of Transition Amount	0		0
Amortization of Losses	9,002		13,194
Net Amortization and Deferral For Regulatory Purposes (Including Volumetric Adjustments)	1,578	[1]	(3,682)	[1]
Net Periodic Benefit Cost	9,529		8,321
Other Post-Retirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	735		1,176
Interest Cost	5,327		4,803
Expected Return on Plan Assets	(9,356)		(8,218)
Amortization of Prior Service Cost (Credit)	(534)		(534)
Amortization of Transition Amount	0		2
Amortization of Losses	661		5,223
Net Amortization and Deferral For Regulatory Purposes (Including Volumetric Adjustments)	6,060	[1]	2,703	[1]
Net Periodic Benefit Cost	$ 2,893		$ 5,155

[1] The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.