Commitments and Contingencies - Narrative (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) Facility	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Committed total of property, plant and equipment expenditure	$ 46.8
Severance payments related to restructuring	20.2
Commitments for outsourced services	111.3
Commitment to purchase natural gas	7.3
Operating lease commitments	459.0
Minimum non-cancelable sublease rental commitments	33.9
Rent expense	$ 172.2	$ 173.2	$ 149.4
Number of sites cited as potentially responsible party | Facility	12
Number of previously and currently owned sites with potential remediation obligations | Facility	10