Long-Term Debt (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 21, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument
Debt, long-term and short-term, combined amount, total		$ 939,000	$ 609,900
Current portion of long-term debt		0	(116,300)
Unamortized debt issuance expense		(9,500)	(4,700)
Unamortized debt discount	$ (14,000)	0	(7,700)
Long-term debt		929,500	481,200
Payments of debt issuance costs and deferred financing fees	(9,600)
Deferred financing fees		1,500
Proceeds from debt, net of discount and issuance costs	776,400
Loss on extinguishment and refinancing of debt, net		17,600	1,600	$ 0
Long-Term Debt, Maturity, Year One		0
Long-Term Debt, Maturity, Year Two		0
Long-Term Debt, Maturity, Year Three		0
Long-Term Debt, Maturity, Year Four		0
Long-Term Debt, Maturity, Year Five		99,000
Estimated future interest payments on debt		324,400
Estimated future interest payments on debt, next 12 months		65,600
Bridge Loan
Debt Instrument
Proceeds from issuance of long-term debt	1,225,000
Interest costs incurred	2,200
Repayments of Debt	(1,225,000)
Term Loan
Debt Instrument
Debt, long-term and short-term, combined amount, total		0	609,900
Proceeds from issuance of long-term debt	$ 700,000
Discount percentage on debt instrument	98.00%
Repayments of Debt		(519,800)
Loss on extinguishment and refinancing of debt, net		(17,600)
Periodic payment of long-term debt principal		8,750
Excess cash flow prepayment		81,400	28,800
Write-off of Unamortized Debt Premium		6,900
Write-off of Interest Rate Swap Loss, previously recorded in AOCI		6,100
Write off of Deferred Debt Issuance Cost		4,600
Letter of Credit
Debt Instrument
Maximum borrowing capacity on line of credit		20,000
Revolving Credit Facility
Debt Instrument
Debt, long-term and short-term, combined amount, total		99,000	0
Maximum borrowing capacity on line of credit		250,000
Proceeds from borrowing under line of credit		164,000
Repayments of lines of credit		(65,000)
Remaining borrowing capacity on line of credit		151,000
Letters of credit outstanding, amount			0
7.00% Senior Notes Maturing in March 2030
Debt Instrument
Debt, long-term and short-term, combined amount, total		840,000	0
Long-term Debt, Gross		840,000
Old Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity on line of credit		200,000
Proceeds from borrowing under line of credit			20,000	195,000
Repayments of lines of credit	$ (20,000)		(50,000)	$ (165,000)
Remaining borrowing capacity on line of credit			200,000
Letters of credit outstanding, amount			$ 0
Proceeds from issuance of long-term debt	$ 100,000
Letter of Credit - Old Credit Agreement
Debt Instrument
Maximum borrowing capacity on line of credit		20,000
Senior Notes [Member] | 7.00% Senior Notes Maturing in March 2030
Debt Instrument
Long-term Debt, Gross		840,000
Payments of debt issuance costs and deferred financing fees		$ (10,200)