XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.20.2

Organization and Basis of Presentation - Additional Information (Detail) | Sep. 30, 2020
--- | ---
Contran | Valhi Incorporation |
Basis Of Presentation And Significant Accounting Policies [Line Items] |
Parent company ownership interest | 92.00%

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Basis of presentation and significant accounting policies. + References No definition available. + Details
Name: | vhi_BasisOfPresentationAndSignificantAccountingPoliciesLineItems
Namespace Prefix: | vhi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=vhi_ContranMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=vhi_ValhiIncorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |