Debt (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Apr. 01, 2021
Line of Credit Facility [Line Items]
Amortization of debt issuance costs and discounts	$ 459,000	$ 518,000	$ 926,000	$ 1,044,000
Maximum
Line of Credit Facility [Line Items]
Accounts receivable from securitization					$ 150,000,000
2021 Credit Agreement | Term Loan
Line of Credit Facility [Line Items]
Amount of loan					475,000,000
Revolving Credit Facility | 2021 Credit Agreement
Line of Credit Facility [Line Items]
Credit facility borrowing capacity					350,000,000
Letter of Credit | 2021 Credit Agreement
Line of Credit Facility [Line Items]
Credit facility borrowing capacity					$ 60,000,000