Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

No definition available.

Name:	dei_AmendmentFlag
Namespace Prefix:	dei_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

PCAOB issued Audit Firm Identifier

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2021	Mar. 07, 2022	Jun. 30, 2021
Document Information [Line Items]
Entity Registrant Name	PZENA INVESTMENT MANAGEMENT, INC.
Entity Central Index Key	0001399249
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Trading Symbol	PZN
Entity Emerging Growth Company	false
Entity Small Business	true
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 191.7
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
City Area Code	212
Document Annual Report	true
Document Transition Report	false
Entity Address, Address Line One	320 Park Avenue
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10022
Entity File Number	001-33761
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8999751
Entity Interactive Data Current	Yes
Local Phone Number	355-1600
Security Exchange Name	NYSE
Title of 12(b) Security	Class A Common Stock, par value $.01 per share
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s definitive proxy statement relating to its 2022 annual meeting of shareholders (the “2022 Proxy Statement”) are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The 2022 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Auditor Firm ID	238
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	New York, New York, USA
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		17,238,355
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		56,603,740