This element represents the amount of recognized equity-based issuances to employees during the period.

No definition available.

Name:	pzn_AdjustmentsToAdditionalPaidInCapitalAndNoncontrollingInterestsEquityIssuance
Namespace Prefix:	pzn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Company's directors have elected to defer percentage of their compensation in the form of phantom shares of Class A common stock under director plan.

+ References

No definition available.

+ Details

Name:	pzn_DeferCompensationPercentageOfCompensationDirectorsElected
Namespace Prefix:	pzn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued pursuant to the terms of a deferred compensation arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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-Publisher FASB
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-SubTopic 10
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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

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

- Definition

Number of options vested.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued which are neither cancelled nor held in the treasury.

+ References

No definition available.

+ Details

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

- Definition

Number of shares of capital stock issued (purchased by employees) in connection with an employee stock ownership plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

+ References

No definition available.

+ Details

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

- Definition

Value of forfeitures of stock or other type of equity issued of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

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-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 2
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=pzn_PhantomSharesOfClassCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pzn_BonusPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Compensation and Benefits - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Compensation Arrangements [Line Items]
New non-cash compensation awards were issued	0	0
Delayed Exchange Class B units issued			$ 5,191	$ 187
Deferred compensation liability	$ 3,490		3,490		$ 918
Unrecorded compensation expense	$ 27,700		$ 27,700		$ 32,600
Phantom Shares of Class A common stock \| Director
Compensation Arrangements [Line Items]
Deferred compensation percentage of compensation directors elected			100.00%
Shares outstanding (in shares)	386,377		386,377		336,016
Distributions made under Director Plan (in shares)	0	0	0	0
Common Class B
Compensation Arrangements [Line Items]
Delayed Exchange Class B units issued (in shares)			897,515	29,426
Common Stock \| Common Class B
Compensation Arrangements [Line Items]
Delayed Exchange Class B units issued (in shares)	479	15,749	897,515	29,426
Delayed Exchange Class B units issued		$ 100	$ 5,200	$ 200
Common Stock \| Common Class B \| Maximum
Compensation Arrangements [Line Items]
Delayed Exchange Class B units issued	$ 100
Equity Incentive Plan 2006
Compensation Arrangements [Line Items]
Cash compensation paid in the form of equity					$ 4,200
2007 Equity Incentive Plan \| Contingent Options to Purchase Shares of Class A Common Stock
Compensation Arrangements [Line Items]
Contingently vesting options (in shares)	0	0	0	0
Bonus plan
Compensation Arrangements [Line Items]
Vesting period for units (in years)			4 years
Value of stock forfeited	$ 300