v3.8.0.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2017
Feb. 22, 2018
Jun. 30, 2017
Document And Entity Information [Abstract]      
Entity Registrant Name ENCORE WIRE CORP    
Entity Trading Symbol WIRE    
Entity Central Index Key 0000850460    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Document Type 10-K    
Document Period End Date Dec. 31, 2017    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus (i.e. Q1,Q2,Q3,FY) FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   20,835,748  
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 754,677,665