Capitalization And Short-Term Borrowings (Narrative) (Details)				12 Months Ended
	Jun. 03, 2020 USD ($)	Jun. 02, 2020 USD ($) $ / shares shares	Aug. 17, 2018 USD ($)	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 07, 2018 USD ($)	Sep. 27, 2017 USD ($)
Debt Instrument [Line Items]
Issue shares of common stock for the Direct Stock Purchase and Dividend Reinvestment Plan | shares				0
Common stock issued for 401(k) plans | shares				0
Shares tendered | shares				91,545
Share-Based Payment Expense				$ 13,100,000	$ 19,500,000	$ 14,200,000
Tax benefit related to stock-based compensation expense				2,100,000	3,800,000	3,400,000
Capitalized stock-based compensation costs				100,000	100,000	100,000
Unamortized Debt Expense				12,297,000	14,005,000
Gain (Loss) on Extinguishment of Debt						1,000,000.0
Net proceeds from issuance of long-term debt				493,007,000	0	$ 295,020,000
Principal amounts of long-term debt maturing in 2021				0
Principal amounts of long-term debt maturing in 2022				500,000,000.0
Principal amounts of long-term debt maturing in 2023				549,000,000.0
Principal amounts of long-term debt maturing in 2024				0
Principal amounts of long-term debt maturing in 2025				500,000,000.0
Principal amounts of long-term debt maturing after 2025				1,100,000,000.0
Commercial paper, outstanding				15,000,000.0	$ 55,200,000
Short-term notes payable outstanding				$ 15,000,000.0
Committed credit facility maximum debt to capitalization ratio				0.65
Ceiling Test Impairment Adjustment				50.00%
Ceiling Test Impairment Maximum Adjustment				$ 250,000,000
Debt to capitalization ratio				0.55
Additional borrowing				$ 1,300,000,000
Aggregated indebtedness				$ 40,000,000.0
Preferred stock, shares authorized | shares				10,000,000
Preferred stock par value | $ / shares				$ 1
Percentage of Long-Term Debt issued under 1974 Indenture				3.70%
Common Stock, Par Value | $ / shares				$ 1	$ 1
Cumulative after-tax ceiling test impairments since July 1, 2018				$ 326,300,000
Committed Credit Facility Debt to Capitalization Ratio Ceiling Test Impairment Adjustment Amount				163,100,000
Tax expense related to stock-based compensation exercises and vestings				$ 3,200,000
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Weighted average interest rate				1.51%
June 2, 2020 Public Offering of Common Stock [Member]
Debt Instrument [Line Items]
Common Stock Issued from Sale of Common Stock (Shares) | shares		4,370,000
Common Stock, Par Value | $ / shares		$ 1.00
Common Stock Issued, Price Per Share | $ / shares		$ 39.50
Proceeds from Issuance of Common Stock		$ 165,800,000
Stock Appreciation Rights (SARs) [Member]
Debt Instrument [Line Items]
Number of Shares Granted | shares				0	0	0
Total intrinsic value of SAR's exercised					$ 7,200,000	$ 4,400,000
Number of Awards Vested | shares				0	0	0
Restricted Share Awards [Member]
Debt Instrument [Line Items]
Number of Shares Granted | shares				0	0	0
Weighted Average Fair Value per Award Granted | $ / shares				$ 0
Number of Awards Vested | shares				0
Unrecognized compensation expense				$ 100,000
Unrecognized compensation expense recognized weighted average period				1 month 6 days
Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Number of Shares Granted | shares				150,839	123,939	89,672
Weighted Average Fair Value per Award Granted | $ / shares				$ 40.38	$ 49.40	$ 51.23
Number of Awards Vested | shares				87,835
Unrecognized compensation expense				$ 6,300,000
Unrecognized compensation expense recognized weighted average period				2 years 1 month 6 days
Performance Shares [Member]
Debt Instrument [Line Items]
Common stock issued | shares				231,246
Number of Shares Granted | shares				254,608	244,734	208,588
Weighted Average Fair Value per Award Granted | $ / shares				$ 43.32	$ 55.67	$ 50.95
Number of Awards Vested | shares				231,246
Unrecognized compensation expense				$ 10,600,000
Unrecognized compensation expense recognized weighted average period				1 year 8 months 12 days
Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Common stock issued | shares				87,835
Board Of Directors [Member]
Debt Instrument [Line Items]
Common stock issued | shares				41,873
3.95% Notes Due September 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, face value								$ 300,000,000.0
Long-term debt, interest rate								3.95%
4.75% Notes Due September 1, 2028 [Member]
Debt Instrument [Line Items]
Long-term debt, face value			$ 300,000,000.0
Long-term debt, interest rate			4.75%
Net proceeds from issuance of long-term debt			$ 295,000,000.0
8.75% Notes Due May 2019 [Member]
Debt Instrument [Line Items]
Long-term debt, face value							$ 250,000,000.0
Long-term debt, interest rate							8.75%
Debt Instrument redeemed						$ 259,500,000
Unamortized Debt Expense						8,500,000
6.50% Notes Due April 2018 [Member]
Debt Instrument [Line Items]
Long-term debt, face value						$ 300,000,000.0
Long-term debt, interest rate						6.50%
Debt Instrument redeemed						$ 307,000,000.0
5.50% Notes Due January 15, 2026 [Member]
Debt Instrument [Line Items]
Long-term debt, face value	$ 500,000,000.0
Long-term debt, interest rate	5.50%
Net proceeds from issuance of long-term debt	$ 493,000,000.0
5.50% Notes Due January 15, 2026 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate				7.50%
Indenture From 1974 [Member]
Debt Instrument [Line Items]
Carrying Amount				$ 99,000,000.0
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial paper available				$ 500,000,000.0
Weighted average interest rate				0.25%	2.50%
4.90% Notes Due December 2021 [Member]
Debt Instrument [Line Items]
Long-term debt, face value				$ 500,000,000
Long-term debt, interest rate				4.90%
Fourth Amended & Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 750,000,000.0
364-Day Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 200,000,000.0
2021 [Member] | Restricted Share Awards [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				20,000
2021 [Member] | Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				105,960
2021 [Member] | Performance Shares [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				169,912
2022 [Member] | Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				97,870
2022 [Member] | Performance Shares [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				176,160
2023 [Member] | Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				82,373
2023 [Member] | Performance Shares [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				246,556
2024 [Member] | Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				32,570
2025 [Member] | Non-Performance Based Restricted Stock Units (RSUs) [Member]
Debt Instrument [Line Items]
Non-vested stock-based compensation lapse | shares				17,000