Supplemental Financial Information - Disaggregation of Sales by Timing of Revenue Recognized and Revenue by Category (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Net revenues	$ 373.4	$ 332.8
Suspended Operations
Disaggregation of Revenue [Line Items]
Net revenues		(0.2)
Oil Change And Related Fees
Disaggregation of Revenue [Line Items]
Net revenues	277.5	247.2
Non-oil Change And Related Fees
Disaggregation of Revenue [Line Items]
Net revenues	78.2	69.8
Franchise Fees And Other
Disaggregation of Revenue [Line Items]
Net revenues	17.7	15.8
Net revenues transferred at a point in time
Disaggregation of Revenue [Line Items]
Net revenues	355.9	317.2
Franchised revenues transferred over time
Disaggregation of Revenue [Line Items]
Net revenues	$ 17.5	$ 15.6