Goodwill And Intangible Assets (Summary Of Intangible Assets) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 21.8
Finite-Lived Intangible Assets, Amortization Expense, Year Two	26.5
Finite-Lived Intangible Assets, Amortization Expense, Year Three	$ 24.1
Weighted Average Amortization Period of Finite Lived Assets (in years)	16 years
Gross Asset	$ 552.2	$ 546.7
Accumulated Amortization	273.4	264.5
Net	278.8	282.2
Finite-Lived Intangible Assets, Net	278.8	282.2	$ 317.1
Finite-Lived Intangible Assets, Amortization Expense, Year Four	20.1
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 159.1
Intellectual Property Rights
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period of Finite Lived Assets (in years)	16 years 4 months 24 days
Gross Asset	$ 86.8	86.4
Accumulated Amortization	52.7	52.1
Net	$ 34.1	34.3
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period of Finite Lived Assets (in years)	15 years 9 months 18 days
Gross Asset	$ 393.8	388.9
Accumulated Amortization	160.5	153.4
Net	$ 233.3	235.5
Drawings
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period of Finite Lived Assets (in years)	37 years 10 months 24 days
Gross Asset	$ 11.1	11.1
Accumulated Amortization	10.3	10.3
Net	$ 0.8	0.8
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period of Finite Lived Assets (in years)	13 years
Gross Asset	$ 60.5	60.3
Accumulated Amortization	49.9	48.7
Net	$ 10.6	$ 11.6