Contingencies - Additional Information (Detail) BRL in Millions, $ in Millions	1 Months Ended				9 Months Ended
	May 31, 2016 USD ($)	Jan. 31, 2012 USD ($)	Nov. 22, 2011 USD ($)	Nov. 22, 2011 BRL	Sep. 30, 2016 BRL	May 31, 2012 USD ($)	Jun. 30, 2010 USD ($)
Loss Contingencies [Line Items]
Damages asserted by BK | BRL					BRL 20.8
Accrual for Environmental Loss Contingencies							$ 100.0
Business combination, recognized identifiable assets acquired and liabilities assumed, contingent liability						$ 2.9
Litigation Settlement, Amount		$ 0.1
Court-Imposed Interest, Fees or Inflation Adjustments
Loss Contingencies [Line Items]
Total ordered damages granted to Bk			$ 8.2
Court-Imposed Interest, Fees or Inflation Adjustments | Maximum
Loss Contingencies [Line Items]
Total ordered damages granted to Bk | BRL				BRL 26.7
Arizona Department Of Environmental Quality
Loss Contingencies [Line Items]
Payments for Legal Settlements	$ 0.2