Represents consideration received from conversion of stock.

No definition available.

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

- Definition

Represents the conversion ratio of common stock.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of classes of common stock.

+ References

No definition available.

+ Details

Name:	pfsi_NumberOfClassesOfCommonStock
Namespace Prefix:	pfsi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of indirect controlled subsidiaries that entered into Amended and Restated Master Purchase Agreement.

+ References

No definition available.

+ Details

Name:	pfsi_NumberOfIndirectControlledSubsidiariesThatEnteredIntoAmendedAndRestatedMasterPurchaseAgreement
Namespace Prefix:	pfsi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of non-affiliate sellers of bulk portfolio.

+ References

No definition available.

+ Details

Name:	pfsi_NumberOfNonAffiliateSellersOfBulkPortfolio
Namespace Prefix:	pfsi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount purchased of unpaid principal balance of mortgage servicing rights related to defaulted government loans.

+ References

No definition available.

+ Details

Name:	pfsi_PurchasedMortgageServicingRightsUnpaidPrincipalBalanceDefaultedGovernmentLoans
Namespace Prefix:	pfsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the maximum aggregate transaction amount per the amended repurchase agreement.

+ References

No definition available.

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ 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
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TransactionTypeAxis=pfsi_SyndicatedRepurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=pfsi_NewPennyMacFinancialServicesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
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

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

- Details

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

Subsequent Events (Details) - Subsequent Event $ in Thousands		1 Months Ended
	Nov. 01, 2018 USD ($) item	Oct. 31, 2018 USD ($) item	Oct. 29, 2018 USD ($) item
Subsequent Event
Number of classes of common stock \| item	1	2
Maximum loan amount	$ 150,000
Number of non-affiliate sellers of bulk portfolio \| item		2
Purchase of UPB of Ginnie Mae MSRs		$ 3,200,000
Syndicated Repurchase Agreement
Subsequent Event
Number of indirect controlled subsidiaries that entered into Amended and Restated Master Purchase Agreement. \| item			2
New PFSI \| Class A Common Stock
Subsequent Event
Common stock conversion ratio (as a percent)	100.00%
New PFSI \| Class B Common Stock
Subsequent Event
Consideration received from conversion of stock	$ 0
New PFSI \| Class A Unit
Subsequent Event
Common stock conversion ratio (as a percent)	100.00%
PLS \| Syndicated Repurchase Agreement
Securities Sold under Agreements to Repurchase [Abstract]
Maximum aggregate transaction amount			$ 500,000