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.

No definition available.

+ Details

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

- Definition

The number of general partner units outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187171-122770

+ Details

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

- Definition

Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

+ References

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	srt_OwnershipAxis=ab_AllianceBernsteinL.P.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Business Description, Organization and Basis of Presentation (Details) - shares	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Ownership structure of AB Holding
Units outstanding (in units)	100,000	100,000
EQH \| AXA
Ownership structure of AB Holding
General partnership interest (percent)	10.00%
AB Holding \| EQH
Ownership structure of AB Holding
General partnership interest (percent)	4.20%
AB Holding \| AllianceBernstein Corporation
Ownership structure of AB Holding
General partnership interest (percent)	1.00%
Units outstanding (in units)	100,000
Limited partners or members ownership interest in Company (percent)	35.50%
EQH and its subsidiaries \| AllianceBernstein Corporation
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	63.80%
Unaffiliated holders \| AllianceBernstein Corporation
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	0.70%
AB \| AllianceBernstein Corporation
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	100.00%
AB \| EQH and its subsidiaries
Ownership structure of AB Holding
General partnership interest (percent)	65.30%