Capitalization (Narrative) (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2024 USD ($) $ / shares shares	Jan. 30, 2025 bank	Sep. 30, 2024 USD ($)	May 31, 2024 USD ($) bank	Apr. 01, 2024 USD ($)	Mar. 08, 2024 USD ($)	Feb. 29, 2024 bank	Feb. 14, 2024 USD ($) lender	Feb. 28, 2022 USD ($) bank
Debt Instrument [Line Items]
Stock repurchase program, authorized amount						$ 200,000
Share Repurchases (in shares) | shares	393,038
Current Portion of Long-Term Debt	$ 500,000		$ 500,000
Share Repurchase Plan
Debt Instrument [Line Items]
Share Repurchases (in shares) | shares	548,596
Share repurchase program, average cost per share (in dollars per share) | $ / shares	$ 61.27
Share Repurchases	$ 33,900
Credit Agreement
Debt Instrument [Line Items]
Number of banks In syndicate | bank				3			11		12
Maximum borrowing capacity				$ 1,000,000					$ 1,000,000
Extended term of credit agreement							1 year
Credit Agreement | Subsequent Event
Debt Instrument [Line Items]
Number of banks In syndicate | bank		11
Extended term of credit agreement		1 year
7.38% Notes Due June 2025
Debt Instrument [Line Items]
Current Portion of Long-Term Debt	$ 50,000		$ 50,000
Long-term debt, interest rate	7.38%		7.38%
5.20% Notes Due July 2025
Debt Instrument [Line Items]
Current Portion of Long-Term Debt	$ 450,000		$ 450,000
Long-term debt, interest rate	5.20%		5.20%
Term Loan Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity								$ 300,000
Number of lenders | lender								6
Long-term debt, face amount					$ 300,000
Proceeds from debt, net of issuance costs	$ 299,400
Rate adjustment to SOFR	0.0010
Spread on variable rate	1.375%
Term Loan Agreement | 5.78% Through February 2025
Debt Instrument [Line Items]
Long-term debt, variable interest rate	5.78%