Capitalization And Short-Term Borrowings (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 18, 2017
Debt Instrument [Line Items]
Total Long-Term Debt		$ 2,399,000	$ 2,099,000
Less Unamortized Discount and Debt Issuance Costs		15,319	12,748
Less Current Portion	[1]	300,000	0
Long-term Debt, Net of Current Portion and Unamortized Discount and Debt Issuance Costs		2,083,681	2,086,252
Debt Instrument redeemed		307,000
6.50% Notes Due April 2018 [Member]
Debt Instrument [Line Items]
Long-term debt, face value		$ 300,000
Long-term debt, interest rate		6.50%
3.95% Notes Due September 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, face value				$ 300,000
Long-term debt, interest rate				3.95%
Maximum interest rate adjustment		2.00%
7.4% Due March 2023 To June 2025 [Member]
Debt Instrument [Line Items]
Medium-Term Notes	[2]	$ 99,000	$ 99,000
Long-term debt, interest rate		7.40%	7.40%
3.75% To 8.75% Due April 2018 To September 2027 [Member]
Debt Instrument [Line Items]
Notes	[2],[3],[4]	$ 2,300,000	$ 2,000,000
Percentage of principal amount		101.00%	101.00%
Minimum [Member] | 3.75% To 8.75% Due April 2018 To September 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate		3.75%	3.75%
Maximum [Member] | 3.75% To 8.75% Due April 2018 To September 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate		8.75%	8.75%

[1] Current Portion of Long-Term Debt at September 30, 2017 consisted of $300.0 million of 6.50% notes scheduled to mature in April 2018. The Company redeemed these notes on October 18, 2017 for $307.0 million, plus accrued interest. The call premium was recorded to Unamortized Debt Expense on the Consolidated Balance Sheet in October 2017.

[2] The Medium-Term Notes and Notes are unsecured.

[3] The holders of these notes may require the Company to repurchase their notes at a price equal to 101% of the principal amount in the event of both a change in control and a ratings downgrade to a rating below investment grade.

[4] The interest rate payable on $300.0 million of 3.95% notes will be subject to adjustment from time to time, with a maximum of 2.00%, if certain change of control events involving a material subsidiary result in a downgrade of the credit rating assigned to the notes to below investment grade (or if the credit rating assigned to the notes is subsequently upgraded).