Capitalization And Short-Term Borrowings (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Feb. 24, 2021	Jun. 03, 2020
Debt Instrument [Line Items]
Total Long-Term Debt		$ 2,649,000	$ 2,649,000
Unamortized Discount and Debt Issuance Costs		16,591	20,313
Current Portion of Long-Term Debt	[1]	549,000	0
Long-term Debt, Net of Current Portion and Unamortized Discount and Debt Issuance Costs		2,083,409	2,628,687
4.75% Notes Due September 1, 2028 [Member]
Debt Instrument [Line Items]
Long-term debt, face value		$ 300,000
Long-term debt, interest rate		4.75%
Maximum interest rate adjustment		2.00%
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%
5.50% Notes Due January 15, 2026 [Member]
Debt Instrument [Line Items]
Long-term debt, face value					$ 500,000
Long-term debt, interest rate					5.50%
Maximum interest rate adjustment		2.00%
2.95% To 5.50% Due March 2023 To March 2031 [Member]
Debt Instrument [Line Items]
Notes	[2],[3],[4]	$ 2,550,000	$ 2,550,000
Percentage of principal amount		101.00%	101.00%
2.95% Notes Due March 1, 2031 [Member]
Debt Instrument [Line Items]
Long-term debt, face value				$ 500,000
Long-term debt, interest rate				2.95%
Maximum interest rate adjustment		2.00%
7.395% Notes Due March 2023
Debt Instrument [Line Items]
Current Portion of Long-Term Debt		$ 49,000
Long-term debt, interest rate		7.395%
3.75% Notes Due March 2023
Debt Instrument [Line Items]
Current Portion of Long-Term Debt		$ 500,000
Long-term debt, interest rate		3.75%
3.75% Notes Due March 2023 | Debt Committed to Redemption
Debt Instrument [Line Items]
Current Portion of Long-Term Debt		$ 150,000
Minimum [Member] | 2.95% To 5.50% Due March 2023 To March 2031 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate		2.95%	2.95%
Maximum [Member] | 5.50% Notes Due January 15, 2026 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate		7.50%
Maximum [Member] | 2.95% To 5.50% Due March 2023 To March 2031 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate		5.50%	5.50%

[1] Current Portion of Long-Term Debt at September 30, 2022 consists of $500.0 million of 3.75% notes and $49.0 million of 7.395% notes that each mature in March 2023. The Company has committed to redeeming $150.0 million of the 3.75% notes on November 25, 2022. None of the Company's long-term debt as of September 30, 2021 had a maturity date within the following twelve-month period.

[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 4.75% notes, $300.0 million of 3.95% notes and $500.0 million of 2.95% 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). The interest rate payable on $500.0 million of 5.50% notes will be subject to adjustment from time to time, with a maximum adjustment of 2.00%, such that the coupon will not exceed 7.50%, if there is a downgrade of the credit rating assigned to the notes to a rating below investment grade. A downgrade with a resulting increase to the coupon does not preclude the coupon from returning to its original rate if the Company's credit rating is subsequently upgraded.