Nature of Operations and Significant Accounting Policies (Summary Of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 437.5	$ 384.9
Finite-Lived Intangible Assets, Net	520.3	505.1	$ 481.8	$ 276.8
Intangible Assets, Gross (Excluding Goodwill)	$ 957.8	890.0
Finite-Lived Intangible Asset, Useful Life	17 years 7 months 6 days
Intangibles with indefinite useful lives	$ 70.9	69.9
Intellectual Property Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	58.4	56.8
Finite-Lived Intangible Assets, Net	79.8	77.4
Intangible Assets, Gross (Excluding Goodwill)	$ 138.2	134.2
Finite-Lived Intangible Asset, Useful Life	15 years 8 months 12 days
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 88.0	76.3
Finite-Lived Intangible Assets, Net	56.9	65.3
Intangible Assets, Gross (Excluding Goodwill)	$ 144.9	141.6
Finite-Lived Intangible Asset, Useful Life	11 years 9 months 18 days
Drawings [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 10.5	10.5
Finite-Lived Intangible Assets, Net	0.6	0.6
Intangible Assets, Gross (Excluding Goodwill)	$ 11.1	11.1
Finite-Lived Intangible Asset, Useful Life	40 years
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 280.6	241.3
Finite-Lived Intangible Assets, Net	383.0	361.8
Intangible Assets, Gross (Excluding Goodwill)	$ 663.6	$ 603.1
Finite-Lived Intangible Asset, Useful Life	18 years