Intangible Assets and Goodwill Intangible Assets (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019	Jan. 31, 2020	Nov. 21, 2019
Intangible Assets [Line Items]
Intangible asset impairment		$ 10,200,000
Finite-Lived Intangible Assets, Gross	$ 1,174,900,000	1,174,900,000	$ 600,100,000
Finite-Lived Intangible Assets, Accumulated Amortization	(311,100,000)	(311,100,000)	(270,700,000)
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	71,300,000	71,300,000
Intangible Assets, Gross (Excluding Goodwill)	1,412,400,000		725,600,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	65,200,000	65,200,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	64,200,000	64,200,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	63,700,000	63,700,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	63,600,000	63,600,000
Trade names
Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	237,500,000	$ 237,500,000	125,500,000
Minimum
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		3 years
Maximum
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		21 years
Trade names
Intangible Assets [Line Items]
Intangible asset impairment		$ 8,600,000
Finite-Lived Intangible Assets, Gross	200,000	200,000	200,000
Finite-Lived Intangible Assets, Accumulated Amortization	(200,000)	(200,000)	(200,000)
Customer relationships
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	943,000,000.0	943,000,000.0	464,200,000
Finite-Lived Intangible Assets, Accumulated Amortization	(191,200,000)	(191,200,000)	(169,200,000)
Technology, including patents
Intangible Assets [Line Items]
Intangible asset impairment		1,600,000
Finite-Lived Intangible Assets, Gross	156,000,000.0	156,000,000.0	76,800,000
Finite-Lived Intangible Assets, Accumulated Amortization	(55,400,000)	(55,400,000)	(49,400,000)
Computer Software, Intangible Asset [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	65,600,000	65,600,000	58,700,000
Finite-Lived Intangible Assets, Accumulated Amortization	(54,200,000)	(54,200,000)	(51,700,000)
Backlog
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	10,000,000.0	10,000,000.0
Finite-Lived Intangible Assets, Accumulated Amortization	(10,000,000.0)	(10,000,000.0)
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	100,000	100,000	200,000
Finite-Lived Intangible Assets, Accumulated Amortization	(100,000)	(100,000)	$ (200,000)
Milacron
Intangible Assets [Line Items]
Identifiable intangible assets	815,000,000.0	815,000,000.0		$ (50,000,000.0)	$ 865,000,000.0
Discontinued Operations, Disposed of by Sale [Member] | Cimcool
Intangible Assets [Line Items]
Disposal Group, Including Discontinued Operation, Intangible Assets	$ 122,100,000	$ 122,100,000