Commitments and Contingencies - Additional Information (Detail) $ in Millions	Jun. 30, 2016 USD ($) LegalMatter	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number | LegalMatter	4,000
Liability For Claims And Contingencies	$ 233.0	$ 237.9
Liability Reserve For Insurance Claims	109.0	111.0
Environmental Reserve Other Accrued Costs	19.0	22.8
Letters of credit outstanding	$ 378.3	$ 402.2