Noncontrolling Interest in Subsidiaries - Changes in Ownership Interest in Subsidiaries (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidation Less Than Wholly Owned Subsidiary Parent Ownership Interest Effects Of Changes Net [Line Items]
Net income (loss) attributable to Valhi stockholders	$ 15.7	$ (34.2)	$ (39.7)	$ (39.8)	$ 3.5	$ 23.0	$ 44.3	$ 89.0	$ (98.0)	$ 159.8	$ 217.5
Transfers from noncontrolling interest:
Issuance of subsidiary stock									(0.4)	0.2	0.4
Net income (loss) attributable to Valhi stockholders and change from noncontrolling interest in subsidiaries									$ (98.4)	$ 160.0	$ 217.9