XML 26 R1.htm IDEA: XBRL DOCUMENT v3.19.3
Document and Entity Information - shares
 9 Months Ended
Sep. 30, 2019
Oct. 24, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
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  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Shell Company false  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity File Number 1-13905  
Entity Tax Identification Number 57-0981653  
Entity Address, Address Line One 5430 LBJ Freeway  
Entity Address, Address Line Two Suite 1700  
Entity Address, Address Line Three Three Lincoln Centre  
Entity Address, City or Town Dallas  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 75240  
City Area Code 972  
Local Phone Number 448-1400  
Entity Common Stock, Shares Outstanding   12,443,057
Entity Incorporation, State or Country Code DE  
Title of 12(b) Security Class A common stock  
Security Exchange Name NYSEAMER  
Document Quarterly Report true  
Document Transition Report false