Commitments and Contingencies - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) Cases site Plaintiff	Dec. 31, 2014 USD ($)
Loss Contingencies [Line Items]
Liable periods	twenty-year
Litigation settlement amount	$ 1,150,000
Accrued environmental obligations approximately	$ 111,611	$ 110,015
Sites associated with remediation | site	43
Remediation and related matters possible to estimate costs	$ 166,000
Currently not able to estimate a range of costs to sites | site	5
Product Liability And Occupational Exposure Litigation Claims
Loss Contingencies [Line Items]
Number of cases pending | Cases	166
Administratively Dismissed Claims | Product Liability And Occupational Exposure Litigation Claims
Loss Contingencies [Line Items]
Number of plaintiffs involved | Cases	8,692
Pending Claims | Product Liability And Occupational Exposure Litigation Claims
Loss Contingencies [Line Items]
Number of plaintiffs involved | Plaintiff	712
Minimum
Loss Contingencies [Line Items]
Number of cases administratively dismissed or inactive | Cases	100