Property, Plant and Equipment - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Depreciation expense	$ 82.5	$ 91.4	$ 165.4	$ 179.3
Book value of assets held for sale	$ 6.2		$ 6.2		$ 7.2