XML 12 R1.htm IDEA: XBRL DOCUMENT v3.5.0.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2016
Jul. 28, 2016
Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2016  
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q2  
Trading Symbol CIX  
Entity Registrant Name COMPX INTERNATIONAL INC  
Entity Central Index Key 0001049606  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Class A Common Stock    
Document And Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   2,419,107
Class B Common Stock    
Document And Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   10,000,000