Amount of net assets (liabilities).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77885760&loc=SL35686385-199418

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 205
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=99400292&loc=d3e9915-115836

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-URI http://asc.fasb.org/extlink&oid=114873854&loc=SL114874367-224272

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 2
-Subparagraph (SX 210.6-05(4))
-URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e604008-122996

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(6))
-URI http://asc.fasb.org/extlink&oid=114873854&loc=SL114874367-224272

+ Details

Name:	us-gaap_AssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The net amount (to the extent disclosed within this portion of the income statement) by which an insurance settlement exceeds incremental costs incurred from the event causing an interruption of business, plus the insurance award for earnings lost from the event, such as a natural catastrophe, explosion or fire.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114868897&loc=SL114872001-224240

+ Details

Name:	us-gaap_GainOnBusinessInterruptionInsuranceRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

+ Details

Name:	us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Controlling interest in subsidiary held indirectly through controlled subsidiary of parent.

+ References

No definition available.

+ Details

Name:	vhi_IndirectControllingInterestInSubsidiary
Namespace Prefix:	vhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Water delivery contract revenue percentage.

+ References

No definition available.

+ Details

Name:	vhi_WaterDeliveryContractRevenuePercentage
Namespace Prefix:	vhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Duration in years for water delivery contract.

+ References

No definition available.

+ Details

Name:	vhi_WaterDeliveryContractTerm
Namespace Prefix:	vhi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_StatementGeographicalAxis=vhi_NonUSSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=vhi_ChemicalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=vhi_RealEstateManagementAndDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=vhi_CityOfHendersonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=vhi_IndefiniteLivedCustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=vhi_KronosMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=vhi_ValhiIncorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=vhi_NLIndustriesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=vhi_NLIndustriesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=vhi_LandWellMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=vhi_BasicManagementIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=vhi_BasicManagementIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business and Geographic Segments - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) Segment	Dec. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| Segment		3
Business interruption insurance proceeds			$ 4.3
Contract related intangible asset impairment			5.1
Non-U.S. subsidiaries
Segment Reporting Information [Line Items]
Net assets of non-U.S. subsidiaries		$ 614.0		$ 614.0
Chemicals
Segment Reporting Information [Line Items]
Business interruption insurance proceeds			4.3
Real Estate Management And Development \| City Of Henderson
Segment Reporting Information [Line Items]
Delivery contract extended period		25 years
Water delivery contract revenue, percentage		70.00%
Real Estate Management And Development \| Customer Relationships
Segment Reporting Information [Line Items]
Indefinite-lived intangible asset					$ 5.1
Contract related intangible asset impairment	$ 5.1		$ 5.1
Kronos Worldwide, Inc. \| Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent		50.00%
Kronos Worldwide, Inc. \| NL
Segment Reporting Information [Line Items]
Indirect controlling interest in subsidiary		30.00%
NL \| Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent		83.00%
LandWell \| Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent		27.00%
LandWell \| BMI
Segment Reporting Information [Line Items]
Indirect controlling interest in subsidiary		50.00%
BMI \| Real Estate Management And Development
Segment Reporting Information [Line Items]
Direct ownership percentage by parent		63.00%
BMI \| Valhi Incorporation
Segment Reporting Information [Line Items]
Direct ownership percentage by parent		63.00%