Segment and Geographic Data - Schedule of Revenues by Geographic Location (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	$ 1,046.4	$ 942.7	$ 3,017.0	$ 2,655.2
U.S.
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	772.9	699.1	2,195.9	1,970.7
Canada
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	48.7	43.3	142.5	126.9
Other North America
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	33.3	29.7	99.9	54.9
Total North America Operations
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	854.9	772.1	2,438.3	2,152.5
EMEA
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	139.0	120.9	415.9	342.2
Asia
Revenues by geographic location, based on the jurisdiction of the subsidiary entity receiving revenue credit for the sale
Revenues	$ 52.5	$ 49.7	$ 162.8	$ 160.5