Debt - Schedule of Long-term Debt Obligations (Details) - USD ($)		Jun. 30, 2023	Sep. 30, 2022	Feb. 13, 2020
Debt Instrument [Line Items]
Total debt		$ 1,745,000,000	$ 1,359,000,000
Unamortized debt issuance costs for the senior notes	[1]	(6,759,000)	(8,372,000)
Total debt, net of issuance costs		1,738,241,000	1,350,628,000
4.000% Senior Notes Due 2028
Debt Instrument [Line Items]
Senior Notes				$ 500,000,000
3.625% Senior Notes Due 2025
Debt Instrument [Line Items]
Senior Notes				$ 500,000,000
Long-term Debt [Member] | Line of Credit
Debt Instrument [Line Items]
Credit facility revolvering line	[2],[3]	245,000,000	359,000,000
Credit facility term loan	[2],[3]	500,000,000	0
Long-term Debt [Member] | 4.000% Senior Notes Due 2028
Debt Instrument [Line Items]
Senior Notes		500,000,000	500,000,000
Long-term Debt [Member] | 3.625% Senior Notes Due 2025
Debt Instrument [Line Items]
Senior Notes		$ 500,000,000	$ 500,000,000

[1] Unamortized debt issuance costs for the senior notes are included in Long-term debt on the Consolidated Balance Sheets.

[2] Both the revolving line and the term loan will mature and all amounts then outstanding will become due and payable on January 3, 2028, unless the 2025 notes have not been refinanced to mature on or after April 3, 2028, in which case the amounts will become due on November 16, 2024. The term loan will begin amortizing in March 2024, with payments of $9.4 million in 2024, $21.9 million in 2025, and $25.0 million in each year thereafter.

[3] Unamortized debt issuance costs related to the credit facility were $2.3 million included in Other current assets and $8.1 million included in Other assets on the Consolidated Balance Sheet as of June 30, 2023 and $2.7 million included in Other assets on the Consolidated Balance Sheet as of September 30, 2022.