Revolving Line of Credit	12 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Revolving Line of Credit	We have a $600 million unsecured revolving line of credit with a syndicate of banks that expires on August 19, 2026. Borrowings under the credit facility can be used for working capital and general corporate purposes and may also be used for the refinancing of existing debt, acquisitions, and the repurchase of our common stock. Interest on amounts borrowed under the credit facility is based on (i) an adjusted base rate, which is the greatest of (a) the prime rate, (b) the Federal Funds rate plus 0.500%, and (c) the one-month LIBOR rate plus 1.000%, plus, in each case, an applicable margin, or (ii) an adjusted LIBOR rate plus an applicable margin. The applicable margin for base rate borrowings ranges from 0% to 0.750% and for LIBOR borrowings ranges from 1.000% to 1.750%, and is determined based on our consolidated leverage ratio. In addition, we must pay credit facility fees. The credit facility contains certain restrictive covenants, including a maximum consolidated leverage ratio of 3.50, subject to a step up to 4.00 following certain permitted acquisitions; and a minimum interest coverage ratio of 3.00. The credit agreement also contains other covenants typical of unsecured facilities.On October 20, 2021, we amended our credit agreement to provide for the issuance of a $300 million term loan. The term loan is subject to the same pricing and covenants as the revolving line of credit and matures at the expiration of the facility on August 19, 2026. The term loan requires principal payments in consecutive quarterly installments of $3.75 million on the last business day of each quarter.As of September 30, 2022, we had $280.0 million in borrowings outstanding under the revolving credit facility at a weighted-average interest rate of 4.479%