Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Millions	Jun. 30, 2020	Sep. 30, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Goodwill and other intangible assets	$ 2,932.1	$ 2,963.7
Assets held for sale	0.0	791.7
Total assets	5,126.5	5,449.6
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Tangible assets	2,065.9	1,612.9
Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Tangible assets	128.5	81.3
Americas | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Tangible assets	1,433.6	991.9
International | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Tangible assets	$ 632.3	$ 621.0