Business Segment Information - Holding Percentage of Subsidiaries (Detail)	Mar. 31, 2014
Kronos Worldwide, Inc.
Segment Reporting Information [Line Items]
Controlling interest in subsidiary	80.00%
CompX
Segment Reporting Information [Line Items]
Controlling interest in subsidiary	87.00%
WCS
Segment Reporting Information [Line Items]
Controlling interest in subsidiary	100.00%
BMI and LandWell | Minimum
Segment Reporting Information [Line Items]
Controlling interest in subsidiary	63.00%
BMI and LandWell | Maximum
Segment Reporting Information [Line Items]
Controlling interest in subsidiary	77.00%