Debt - Summary Of Interest Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instruments [Abstract]
Interest incurred	$ 285.2	$ 294.6	$ 276.0
Less: interest income	(5.3)	(8.9)	(11.5)
Less: interest capitalized as property, plant and equipment	(3.9)	(3.6)	(3.1)
Interest expense, net	$ 276.0	$ 282.1	$ 261.4