Capitalization (Narrative) (Details) $ / shares in Units, $ in Thousands		9 Months Ended
	Feb. 28, 2022 USD ($) bank	Jun. 30, 2024 USD ($) $ / shares shares	May 31, 2024 USD ($) bank	Apr. 01, 2024 USD ($)	Mar. 08, 2024 USD ($)	Feb. 29, 2024 bank	Feb. 14, 2024 USD ($) lender	Sep. 30, 2023 USD ($)
Debt Instrument [Line Items]
Stock repurchase program, authorized amount					$ 200,000
Current Portion of Long-Term Debt		$ 50,000						$ 0
Stock and Benefit Plans
Debt Instrument [Line Items]
Share Repurchases (in shares) | shares		77,461
Share Repurchase Plan
Debt Instrument [Line Items]
Share Repurchases (in shares) | shares		526,652
Share repurchase program, average cost per share (in USD per share) | $ / shares		$ 54.28
Share Repurchases		$ 28,800
364-Day Credit Agreement
Debt Instrument [Line Items]
Term	364 days
Credit Agreement
Debt Instrument [Line Items]
Number of banks In syndicate | bank	12		3			11
Maximum borrowing capacity	$ 1,000,000		$ 1,000,000
Term Loan Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 300,000
Number of lenders | lender							6
Long-term debt, face amount				$ 300,000
Weighted average interest rate (as a percent)		6.705%
Proceeds from debt, net of issuance costs		$ 299,400
7.375% Notes Due June 2025
Debt Instrument [Line Items]
Current Portion of Long-Term Debt		$ 50,000
Long-term debt, interest rate		7.375%
Restricted Stock Units
Debt Instrument [Line Items]
Common stock issued (in shares) | shares		112,667
Performance Shares
Debt Instrument [Line Items]
Common stock issued (in shares) | shares		251,255
Board Of Directors
Debt Instrument [Line Items]
Common stock issued (in shares) | shares		27,310
Officer DCP Plan
Debt Instrument [Line Items]
Common stock issued (in shares) | shares		5,964