Document And Entity Information	6 Months Ended
Jun. 30, 2011	Jul. 28, 2011 Class A [Member]	Jul. 28, 2011 Class B [Member]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Entity Filer Category	Non-accelerated Filer
Entity Registrant Name	COMPX INTERNATIONAL INC
Entity Central Index Key	0001049606
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		2,386,107	10,000,000

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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