Intangible Assets and Goodwill Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019	Nov. 21, 2019
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 1,014.5	$ 1,001.1
Finite-Lived Intangible Assets, Accumulated Amortization	(278.2)	(267.2)
Intangible Assets, Gross (Excluding Goodwill)	1,244.1	1,227.9
Trade names
Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	$ 229.6	226.8
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]
Finite-Lived Intangible Assets, Gross	$ 0.2	0.2
Finite-Lived Intangible Assets, Accumulated Amortization	(0.2)	(0.2)
Customer relationships
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	809.2	787.6
Finite-Lived Intangible Assets, Accumulated Amortization	(166.8)	(151.8)
Technology, including patents
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	139.7	137.6
Finite-Lived Intangible Assets, Accumulated Amortization	(55.3)	(51.0)
Computer Software, Intangible Asset [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	65.4	65.6
Finite-Lived Intangible Assets, Accumulated Amortization	(55.9)	(54.1)
Backlog
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0.0		$ 10.0
Finite-Lived Intangible Assets, Accumulated Amortization	0.0		$ (10.0)
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0.0	0.1
Finite-Lived Intangible Assets, Accumulated Amortization	0.0	$ (0.1)
Molding Technology Solutions
Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 815.0			$ 815.0