ClassK [Member] Investment Objectives and Goals - Class K - BLACKROCK LARGE CAP FOCUS VALUE FUND, INC.	Jun. 30, 2026
Prospectus [Line Items]
Risk/Return [Heading]	Fund OverviewKey Facts About BlackRock Large Cap Focus Value Fund, Inc.
Objective [Heading]	Investment Objective
Objective, Primary [Text Block]	The investment objective of BlackRock Large Cap Focus Value Fund, Inc. (the “Fund”) is to seek capital appreciation and,
Objective, Secondary [Text Block]	secondarily, income by investing in securities, primarily equity securities, that management of the Fund believes are undervalued and therefore represent basic investment value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Name:	oef_ObjectivePrimaryTextBlock
Namespace Prefix:	oef_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Name:	oef_ObjectiveSecondaryTextBlock
Namespace Prefix:	oef_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Section 2
-Name Form N-1A
-Subsection a

Name:	dei_DocumentInformationDocumentAxis=bbvfi_ClassKMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=bbvfi_S000002321Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: