v3.8.0.1
Significant Accounting Policies - Narrative (Details)
12 Months Ended
Dec. 31, 2017
USD ($)
segment
customer
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Significant Accounting Policies [Line Items]      
Number of business segments | segment 1    
Percentage of copper use in relation to cost of goods sold 69.70% 65.20% 72.10%
Shipping and handling cost $ 26,200,000 $ 24,100,000 $ 22,700,000
Certificates of deposit $ 30,200,000 $ 0  
Buildings and Improvements | Minimum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 15 years    
Buildings and Improvements | Maximum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 39 years    
Machinery and Equipment | Minimum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 3 years    
Machinery and Equipment | Maximum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 20 years    
Furniture and Fixtures | Minimum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 3 years    
Furniture and Fixtures | Maximum      
Significant Accounting Policies [Line Items]      
Estimated useful lives of property plant and equipment (in years) 15 years    
Customer Concentration Risk | Sales Revenue, Net      
Significant Accounting Policies [Line Items]      
Customer concentration risk, number of customers | customer 2