Derivative Financial Instruments (Schedule of Notional Amounts of Outstanding Derivative Positions) (Details) - Futures	3 Months Ended
Mar. 31, 2018 T
Aluminum \| Long
Derivative [Line Items]
Commodity contract (in MT/Lbs)	1,950
Aluminum \| Short
Derivative [Line Items]
Commodity contract (in MT/Lbs)	2,450
Copper \| Long
Derivative [Line Items]
Commodity contract (in MT/Lbs)	6,078
Copper \| Short
Derivative [Line Items]
Commodity contract (in MT/Lbs)	16,704

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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