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Financial Instruments - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Dec. 30, 2017
Derivative [Line Items]    
Restricted cash in other current assets as collateral related to open derivative contracts $ 1,300 $ 5,300
Commodity Contracts [Member]    
Derivative [Line Items]    
Deferred net losses, net of tax, included in AOCI 287  
Cash Flow Hedging [Member] | Commodity Contracts [Member] | Long [Member]    
Derivative [Line Items]    
Open option contracts written, at fair value $ 47,800  
Time period for open copper future contract purchases 12 months  
Fair value of future contracts with loss position $ 117  
Fair Value Hedging [Member] | Commodity Contracts [Member] | Short [Member]    
Derivative [Line Items]    
Fair value of future contracts with loss position (56)  
Open future contracts to sell copper $ 1,700  
Time period for open copper future contract sales 4 months