Marketable Securities - Additional Information (Detail) (Valhi common stock, USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2013	Dec. 31, 2012
Valhi common stock
Schedule Of Available For Sale Securities [Line Items]
Outstanding common stock, shares	14.4	14.4
Common stock quoted market price per share	$ 19.96	$ 12.50

Number of shares of affiliates held for management investment companies.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column B)

-URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611322-123010

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column B

-Article 12

Name:	us-gaap_InvestmentsInAndAdvancesToAffiliatesBalanceShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant