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Debt - Additional Information (Details)				9 Months Ended
Debt - Additional Information (Details)	Jun. 30, 2023	Feb. 10, 2021 USD ($)	Sep. 25, 2018 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Sep. 24, 2018 USD ($)
Debt Instrument [Line Items]
Debt				$ 1,323,200,000
Deferred debt issuance costs				17,000,000		$ 4,600,000
Deferred debt issuance costs				14,500,000
Interest expense
Debt Instrument [Line Items]
Amortization of debt issuance costs				2,800,000	$ 1,000,000
Senior unsecured notes
Debt Instrument [Line Items]
Fair market value				$ 364,200,000		371,000,000
New Credit Facility
Debt Instrument [Line Items]
Maximum borrowings under credit facility			$ 700,000,000
EBITDA ratio			5.50
Interest coverage ratio			3.00
Effective interest rate on debt facilities (percent)				4.12%	3.98%
New Credit Facility \| Forecast
Debt Instrument [Line Items]
EBITDA ratio	4.50
EBITDA Ratio decrease over period	24 months
New Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowings under credit facility							$ 500,000,000
New Credit Facility and Bond Indenture \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowings under credit facility			$ 400,000,000
Debt instrument term			5 years
New Credit Facility and Bond Indenture \| Revolving Credit Facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			2.25%
New Credit Facility and Bond Indenture \| Revolving Credit Facility \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			1.25%
Term loan A \| Term loan facility
Debt Instrument [Line Items]
Debt instrument term			7 years
Face amount			$ 200,000,000
Debt				$ 194,000,000.0		195,500,000
Amortization rate (percent)			1.00%
Average interest rate on outstanding borrowings (percent)				2.63%
Term loan A \| Term loan facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			2.50%
Term loan A \| Term loan facility \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			1.50%
Term Loan B \| Term loan facility
Debt Instrument [Line Items]
Face amount		$ 350,000,000
Debt term		7 years
Incremental loans		$ 250,000,000
Average interest rate on outstanding borrowings (percent)				4.50%
Term Loan B \| Term loan facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			3.75%
Term Loan B \| Term loan facility \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			2.75%
Term Loan B \| Term loan facility \| Minimum Floor
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)			0.75%
6.875% Senior Unsecured Notes Due 2026 \| Senior unsecured notes
Debt Instrument [Line Items]
Face amount			$ 350,000,000
Interest rate (percent)			6.875%
Redemption price (percent)			100.00%
Amount to be redeemed (percent)			35.00%
Redemption price for equity offerings (percentage)			106.875%
Effective rate (percent)				7.248%
Revolving credit facility - U.S. dollar borrowings \| Revolving Credit Facility
Debt Instrument [Line Items]
Average interest rate on outstanding borrowings (percent)				2.44%
Term loan B facility \| Term loan facility
Debt Instrument [Line Items]
Debt				$ 349,100,000		$ 0