Cover Page	12 Months Ended
	Dec. 31, 2021 USD ($) shares
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-29961
Entity Registrant Name	ALLIANCEBERNSTEIN L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-4064930
Entity Address, Address Line One	501 Commerce Street
Entity Address, City or Town	Nashville
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	37203
City Area Code	615
Local Phone Number	622-0000
Title of 12(g) Security	Units of Limited Partnership Interest
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding | shares	271,453,043
Entity Public Float | $	$ 0
Entity Central Index Key	0001109448
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false