Goodwill And Intangible Assets (Changes To Intangible Assets) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Balance at beginning of period, net of accumulated amortization	$ 282.2	$ 317.1
Amortization expense	(7.2)	(30.7)
Balance at end of period, net of accumulated amortization	278.8	282.2
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)	$ 3.8	$ (4.2)