Name:	pfsi_PayableUnderTaxReceivableAgreementPayments
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents payments made pursuant to tax receivable agreement between the Company and exchanged PennyMac unitholders.

No definition available.

Name:	pfsi_PaymentOfLiabilityToExchangedPnmacUnitHoldersUnderTaxReceivableAgreement
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Percentage of tax benefits under the tax sharing agreement attributable to exchanged PennyMac unit holders.

No definition available.

Name:	pfsi_PercentageOfAmountOfTaxBenefits
Namespace Prefix:	pfsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the reduction in payable related to the Tax Cuts and Jobs Act of 2017.

No definition available.

Name:	pfsi_ReductionInPayableFromTaxCutsAndJobsAct2017
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of the liability resulting from unit exchanges with Private National Mortgage Acceptance Company, LLC, under tax receivable agreement.

No definition available.

Name:	pfsi_RelatedPartyTransactionTaxReceivableAgreementLiabilityFromPrivateNationalMortgageAcceptanceCompanyUnitExchanges
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents revaluation of tax receivable agreement between the company and PennyMac unit holders.

No definition available.

Name:	pfsi_RevaluationOfPayable
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
-URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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

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.