Segments - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Net sales	$ 721.8		$ 658.0	$ 2,255.5	$ 1,981.8
Segment Profit	273.3		263.2	881.7	800.1
Research and development expense	8.2		8.4	24.8	25.6
Amortization of intangible assets	(15.2)		(14.3)	(46.0)	(42.3)
Loss on extinguishment of debt	(27.6)	$ (70.0)	0.0	(103.3)	(4.2)
Other items, net	1.6		(1.1)	1.0	(5.4)
Loss / (earnings) before income taxes	23.6		38.9	97.2	119.5
Acquisition foreign currency gains				13.0
Acquisition and integration costs	19.5		11.4	54.6	47.6
Operating Segments
Segment Reporting Information [Line Items]
Segment Profit	163.5		157.7	551.1	481.3
Segment Reconciling Items
Segment Reporting Information [Line Items]
General corporate and other expenses	(21.5)		(25.6)	(71.3)	(74.0)
Global marketing expense	(9.8)		(7.4)	(28.7)	(19.1)
Research and development expense	8.1		8.2	23.7	24.4
Amortization of intangible assets	(15.2)		(14.3)	(46.0)	(42.3)
Acquisition and integration costs	19.5		11.4	54.6	47.6
Acquisition earn out	(1.2)		0.0	(2.3)	0.0
Interest and other financing items	(38.6)		(50.8)	(125.0)	(144.8)
Americas
Segment Reporting Information [Line Items]
Net sales	525.2		491.9	1,593.8	1,416.3
Americas | Operating Segments
Segment Reporting Information [Line Items]
Net sales	525.2		491.9	1,593.8	1,416.3
Segment Profit	127.7		122.9	415.9	353.9
International
Segment Reporting Information [Line Items]
Net sales	196.6		166.1	661.7	565.5
Acquisition foreign currency gains				12.6
International | Operating Segments
Segment Reporting Information [Line Items]
Net sales	196.6		166.1	661.7	565.5
Segment Profit	35.8		34.8	135.2	127.4
Selling, general and administrate expense
Segment Reporting Information [Line Items]
Global marketing expense	(4.9)		(3.0)	(14.5)	(8.5)
Acquisition and integration costs	9.7		6.1	28.7	25.3
Advertising and Sales Promotion Expense
Segment Reporting Information [Line Items]
Global marketing expense	(4.9)		(4.4)	(14.2)	(10.6)
Research and Development Expense
Segment Reporting Information [Line Items]
Acquisition and integration costs	0.1		0.2	1.1	1.2
Acquisition and integration costs	$ 0.1		$ 0.2	$ 1.1	$ 1.2