Valhi Stockholders' Equity - Additional Information (Detail) shares in Millions	Mar. 31, 2023 shares
Kronos
Schedule Of Stockholders Equity [Line Items]
Shares available for purchase	1.2

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

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