Goodwill And Intangible Assets (Summary Of Intangible Assets) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	18 years
Intangible Assets, Gross (Excluding Goodwill)	$ 816.0	$ 823.6
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	9.7
Finite-Lived Intangible Assets, Amortization Expense, Year Two	36.8
Finite-Lived Intangible Assets, Amortization Expense, Year Three	34.5
Intangible assets, net	445.4	481.8	$ 276.8
Finite-Lived Intangible Assets, Net	445.4
Finite-Lived Intangible Assets, Accumulated Amortization	370.6	341.8
Finite-Lived Intangible Assets, Amortization Expense, Year Four	34.3
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 260.7
Intellectual Property Rights
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years 2 months 12 days
Intangible Assets, Gross (Excluding Goodwill)	$ 129.9	130.7
Intangible assets, net	74.1	75.1
Finite-Lived Intangible Assets, Accumulated Amortization	$ 55.8	55.6
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	18 years 8 months 12 days
Intangible Assets, Gross (Excluding Goodwill)	$ 545.7	546.8
Intangible assets, net	314.4	336.1
Finite-Lived Intangible Assets, Accumulated Amortization	$ 231.3	210.7
Drawings
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	37 years 10 months 24 days
Intangible Assets, Gross (Excluding Goodwill)	$ 11.1	11.1
Intangible assets, net	0.6	0.6
Finite-Lived Intangible Assets, Accumulated Amortization	$ 10.5	10.5
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years 3 months 18 days
Intangible Assets, Gross (Excluding Goodwill)	$ 129.3	135.0
Intangible assets, net	56.3	70.0
Finite-Lived Intangible Assets, Accumulated Amortization	$ 73.0	$ 65.0