Property and Equipment - Property and Equipment, net (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 594.5	$ 571.5
Accumulated depreciation	(350.8)	(311.1)
Total property and equipment, net	243.7	260.4
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	87.3	83.4
Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	453.1	448.1
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	42.5	40.0
Finance Lease Assets [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 11.6	$ 0.0