Derivatives (Outstanding Contracts Designated as Cash Flow Hedges) (Details) - Designated as Hedging Instrument [Member] lb in Millions, MXN in Millions, CAD in Millions	Sep. 30, 2017 CAD lb	Sep. 30, 2017 MXN lb	Dec. 31, 2016 CAD lb	Dec. 31, 2016 MXN lb
Commodity Futures Contracts [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount (in lbs) | lb	18.9	18.9	30.4	30.4
Foreign Exchange Forward [Member] | Mexican Peso [Member]
Derivative [Line Items]
Derivative, notional amount | MXN		MXN 69.8		MXN 310.1
Foreign Exchange Forward [Member] | Canadian Dollar [Member]
Derivative [Line Items]
Derivative, notional amount | CAD	CAD 83.1		CAD 24.9