Commitments and Contingencies - Additional Information (Detail) $ in Millions	Dec. 31, 2015 USD ($) LegalMatter	Dec. 31, 2014 USD ($)
Loss Contingencies [Line Items]
Number Of Claims In Lawsuit | LegalMatter	4,100
Liability For claims and contingencies	$ 237.9	$ 249.1
Liability reserve for insurance claims	111.0	115.8
Environmental Reserve	22.8	31.4
Outstanding Value Of Letters Of Credit	$ 402.2	$ 370.1