Supplemental Financial Information - Disaggregation of Sales by Timing of Revenue Recognized and Revenue by Category (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	$ 332.8	$ 287.3
Suspended Operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	(0.2)	(3.7)
Oil Change And Related Fees
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	247.2	211.5
Non-oil Change And Related Fees
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	69.8	58.3
Franchise Fees And Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	15.8	17.5
Net revenues transferred at a point in time
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	317.2	273.7
Franchised revenues transferred over time
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	$ 15.6	$ 13.6