Long-Term Debt - Revolving Credit Facility - Additional Information (Detail) - Kronos Worldwide, Inc. € in Millions, $ in Millions	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)
Foreign Line of Credit \| Europe
Line Of Credit Facility [Line Items]
Amount available for borrowing	$ 42.2	€ 37.7
Percentage of borrowings available under credit facility	31.00%	31.00%
Revolving North American credit facility
Line Of Credit Facility [Line Items]
Amount available for borrowing	$ 79.2

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant