Business Segment Information - Schedule of Sales and Property by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Sales and property by geographic region
Sales	$ 1,730.2	$ 1,665.1	$ 1,657.2	$ 1,642.3	$ 1,729.5	$ 1,698.7	$ 1,651.2	$ 1,586.6	$ 6,694.8	$ 6,666.0	$ 6,311.3
Property	571.9				576.8				571.9	576.8	583.9
North America
Sales and property by geographic region
Sales									4,014.3	3,964.1	3,801.8
Property	443.8				450.2				443.8	450.2	452.2
Europe, Middle East and Africa
Sales and property by geographic region
Sales									1,249.8	1,286.8	1,193.7
Property	60.5				53.3				60.5	53.3	52.5
Asia Pacific
Sales and property by geographic region
Sales									908.6	933.3	866.4
Property	41.9				42.9				41.9	42.9	40.0
Latin America
Sales and property by geographic region
Sales									522.1	481.8	449.4
Property	$ 25.7				$ 30.4				25.7	$ 30.4	$ 39.2
US
Sales and property by geographic region
Sales									$ 3,640.2