Retirement Plan And Other Post-Retirement Benefits (Schedule Of Benefit Obligations, Plan Assets And Funded Status) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Non-Current Assets	$ 22,774		$ 0
Accrued Benefit Liability	(83,946)		(79,099)
Expected Return on Plan Assets	8.00%
Amortization period	10 years
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit Obligation at Beginning of Period	1,070,744		949,777		924,493
Service Cost	15,846		14,202		14,772
Interest Cost	36,498		41,526		42,676
Plan Participants' Contributions	0		0		0
Retiree Drug Subsidy Receipts	0		0		0
Amendments	0	[1]	0	[1]	(1,764)	[1]
Actuarial (Gain) Loss	(121,631)		120,338		21,395
Benefits Paid	(55,152)		(55,099)		(51,795)
Benefit Obligation at End of Period	946,305		1,070,744		949,777
Fair Value of Assets at Beginning of Period	701,676		601,719		597,549
Actual Return on Plan Assets	98,783		111,034		2,412
Employer Contributions	54,000		44,022		53,553
Fair Value of Assets at End of Period	799,307		701,676		601,719
Net Amount Recognized at End of Period (Funded Status)	(146,998)		(369,068)		(348,058)
Non-Current Liabilities	(146,998)		(369,068)		(348,058)
Non-Current Assets	0		0		0
Accumulated Benefit Obligation	886,942		986,223		874,595
Discount Rate	4.75%		3.50%		4.50%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Expected Return on Plan Assets	(57,346)		(59,701)		(59,103)
Amortization of Prior Service Cost (Credit)	238		269		588
Amortization of Transition Amount	0		0		0
Recognition of Actuarial Loss	52,776	[2]	39,615	[2]	34,873	[2]
Net Amortization and Deferral for Regulatory Purposes	(10,406)		(6,900)		(2,311)
Net Periodic Benefit Cost	37,606		29,011		31,495
Discount Rate	3.50%		4.50%		4.75%
Expected Return on Plan Assets	8.00%		8.25%		8.25%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit Obligation at Beginning of Period	561,263		485,452		472,407
Service Cost	4,705		4,016		4,276
Interest Cost	19,212		21,315		21,884
Plan Participants' Contributions	2,141		1,956		1,963
Retiree Drug Subsidy Receipts	1,526		1,528		1,532
Amendments	0	[1]	0	[1]	(7,187)	[1]
Actuarial (Gain) Loss	(104,455)		71,708		15,071
Benefits Paid	(23,758)		(24,712)		(24,494)
Benefit Obligation at End of Period	460,634		561,263		485,452
Fair Value of Assets at Beginning of Period	414,134		351,990		353,269
Actual Return on Plan Assets	61,715		63,552		(4,094)
Employer Contributions	18,160		21,348		25,346
Fair Value of Assets at End of Period	472,392		414,134		351,990
Net Amount Recognized at End of Period (Funded Status)	11,758		(147,129)		(133,462)
Non-Current Liabilities	(11,016)		(147,129)		(133,462)
Non-Current Assets	22,774		0		0
Accumulated Benefit Obligation
Discount Rate	4.75%		3.50%		4.50%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Expected Return on Plan Assets	(32,872)		(28,971)		(29,165)
Amortization of Prior Service Cost (Credit)	(2,138)		(2,138)		(1,710)
Amortization of Transition Amount	8		10		541
Recognition of Actuarial Loss	20,892	[2]	24,057	[2]	23,794	[2]
Net Amortization and Deferral for Regulatory Purposes	11,844		6,162		10,490
Net Periodic Benefit Cost	$ 21,651		$ 24,451		$ 30,110
Discount Rate	3.50%		4.50%		4.75%
Expected Return on Plan Assets	8.00%		8.25%		8.25%
Rate of Compensation Increase	4.75%		4.75%		4.75%

[1] In fiscal 2011, the Company passed an amendment which changed the definition of annual compensation prospectively to exclude certain bonuses paid by Seneca after September 30, 2011. This decreased the benefit obligation of the Retirement Plan. In fiscal 2011, the Company also increased the prescription drug co-payments for certain retired participants which decreased the benefit obligation of the other post-retirement benefits.

[2] Distribution Corporation’s New York jurisdiction calculates the amortization of the actuarial loss on a vintage year basis over 10 years, as mandated by the NYPSC. All the other subsidiaries of the Company utilize the corridor approach.