Goodwill And Intangible Assets (Summary Of Intangible Assets) (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Document Period End Date	Jun. 30, 2019
Finite-Lived Intangible Asset, Useful Life	17 years 8 months 12 days
Intangible Assets, Gross (Excluding Goodwill)	$ 825.4	$ 823.6
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	20.2
Finite-Lived Intangible Assets, Amortization Expense, Year Two	37.0
Finite-Lived Intangible Assets, Amortization Expense, Year Three	34.6
Intangible assets, net	462.2	481.8	$ 276.8
Finite-Lived Intangible Assets, Net	462.2
Finite-Lived Intangible Assets, Accumulated Amortization	363.2	341.8
Finite-Lived Intangible Assets, Amortization Expense, Year Four	34.4
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 266.1
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)	$ 130.8	130.7
Intangible assets, net	74.7	75.1
Finite-Lived Intangible Assets, Accumulated Amortization	$ 56.1	55.6
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	18 years 4 months 24 days
Intangible Assets, Gross (Excluding Goodwill)	$ 548.5	546.8
Intangible assets, net	322.7	336.1
Finite-Lived Intangible Assets, Accumulated Amortization	$ 225.8	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)	$ 135.0	135.0
Intangible assets, net	64.2	70.0
Finite-Lived Intangible Assets, Accumulated Amortization	$ 70.8	$ 65.0