Income Taxes - Components of Net Deferred Tax Asset and Liability Accounts (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Deferred tax assets:
Interest rate swaps	$ 0.0	$ 1.4
Self-insurance reserves	30.7	29.6
Deferred compensation	3.0	2.7
Payroll related accruals	19.7	18.3
Other accrued expenses	5.4	1.8
Allowance for doubtful accounts	1.0	0.8
Lease liabilities	22.6	17.7
Net operating loss carryforward	8.5	11.2
Other non-current deferred tax assets	3.3	1.8
Total non-current deferred tax assets	94.2	85.3
Total deferred tax assets	94.2	85.3
Deferred tax liabilities:
Intangible assets	47.0	49.0
Property and equipment	78.5	79.0
Deferred revenue	10.6	8.7
Prepaid assets	0.2	0.4
Lease assets	20.9	15.9
Other non-current deferred tax liabilities	0.2	0.5
Total non-current deferred tax liabilities	157.4	153.5
Total deferred tax liabilities	63.2	68.2
Classification on balance sheets:
Other Assets	5.4	2.6
Deferred Tax Liabilities	$ 68.6	$ 70.8