Business Segment Information - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)
Segment Reporting Information [Line Items]
Fixed asset impairment	$ 16.0	$ 16.0
Kronos Worldwide, Inc. | Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent	50.00%	50.00%
Kronos Worldwide, Inc. | NL
Segment Reporting Information [Line Items]
Indirect controlling interest in subsidiary	31.00%	31.00%
NL | Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent	83.00%	83.00%
LandWell | Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent	27.00%	27.00%
LandWell | BMI
Segment Reporting Information [Line Items]
Indirect controlling interest in subsidiary	50.00%	50.00%
BMI | Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent	63.00%	63.00%