Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 104.1	$ 89.8	$ 83.2
Land, buildings and improvements	1,187.3	937.7
Less: Accumulated depreciation	486.6	394.3
Property, plant and equipment, net (Note 10)	700.7	543.4
Land, buildings and improvements
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	201.1	196.9
Machinery, equipment and other
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	$ 637.7	$ 553.1