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Market Concentrations and Risks - Additional Information (Detail) lb in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) lb Customer Distributor	Dec. 31, 2015 USD ($) Customer Distributor	Dec. 31, 2014 Customer Distributor
Concentration Risk [Line Items]
Number of customers | Customer	10	10	10
Number of distributors | Distributor	6	5	5
Long-term debt	$ 1,643,448,000	$ 1,753,021,000
Fair value of debt instrument	1,693,200,000	1,416,600,000
Face value of senior subordinated notes	$ 1,643,448,000.000	$ 1,459,100,000
Copper [Member]
Concentration Risk [Line Items]
Committed amounts to purchase | lb	1.6
Aggregate cost	$ 3,900,000
Recorded unconditional purchase obligation fixed cost	$ (100,000)
Aluminum [Member]
Concentration Risk [Line Items]
Committed amounts to purchase | lb	0.5
Aggregate cost	$ 400,000
Consolidated Revenues [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	33.00%	33.00%	33.00%
Workforce Subject to Collective Bargaining Arrangements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%

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Gain or loss on recorded unconditional purchase obligation based on market value.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Face (par) amount of debt instrument at time of issuance.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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