Commitments and Contingencies - Additional Information (Detail) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017 USD ($) sites	Dec. 28, 2013 USD ($)	Dec. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Document Period End Date	Sep. 30, 2017
Superfund Sites | sites	29
Environmental remediation. Period construction of treatment facility to be maintained	30 years
Centredale Site [Member]
Loss Contingencies [Line Items]
Environmental remediation costs, reserve	$ 68.1
Centredale Site [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Environmental remediation costs deemed probable and reasonably estimable		$ 68.1
Centredale Site [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Environmental remediation costs deemed probable and reasonably estimable		$ 139.7
Property, Plant and Equipment, Other Types
Loss Contingencies [Line Items]
Environmental remediation costs, reserve	175.0		$ 160.9
Reserve for environmental remediation costs, current	21.7
Reserve for environmental remediation costs, noncurrent	153.3
Accrual for Environmental Loss Contingencies, EPA Funded Amount	12.1
Accrual for Environmental Loss Contingencies, Obligation After EPA Funding	162.9
Environmental Remediation Expense	17.1
Property, Plant and Equipment, Other Types | Minimum [Member]
Loss Contingencies [Line Items]
Environmental remediation costs deemed probable and reasonably estimable	142.4
Property, Plant and Equipment, Other Types | Maximum [Member]
Loss Contingencies [Line Items]
Environmental remediation costs deemed probable and reasonably estimable	$ 276.2