Gain Loss On Sales Of Loans From Affiliates.

No definition available.

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

- Definition

Represent fees for services the company performs on behalf of PMT in connection with the acquisition, packaging and sale of mortgage loans.

+ References

No definition available.

+ Details

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

- Definition

Represents the recapture expense incurred relating to mortgage loans subject to either MSRs or ESS owned by a related party that were refinanced by the Company.

+ References

No definition available.

+ Details

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

- Definition

Represents the net gains from sale of mortgage loans to related party.

+ References

No definition available.

+ Details

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

- Definition

the administrative fee plus accrued interest and sourcing fee percent.

+ References

No definition available.

+ Details

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

- Definition

The renewal period that automatically renews at expiration, unless terminated earlier in accordance with the terms of the agreement, for the related party agreement.

+ References

No definition available.

+ Details

Name:	pfsi_RelatedPartyTransactionAgreementTermAutomaticRenewalPeriod
Namespace Prefix:	pfsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Fulfillment fee as a percentage of unpaid principal balance of loans sold or delivered to Fannie Mae or Freddie Mac.

+ References

No definition available.

+ Details

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

- Definition

Represents the the minimum unpaid principal balance of mortgage loans refinanced by the Company, for which a related party previously held the mortgage servicing rights, requiring the Company to transfer the mortgage servicing rights of the new loan to related party.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

Name:	pfsi_RelatedPartyTransactionsLendingActivityAbstract
Namespace Prefix:	pfsi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents a fee paid to a related party relating to mortgage loans purchased from the related party through its correspondent lending activities.

+ References

No definition available.

+ Details

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

- Definition

Represents the tax service fee receivable from transactions with related parties.

+ References

No definition available.

+ Details

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

- Definition

Represents the unpaid principal balance of loans fulfilled.

+ References

No definition available.

+ Details

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

- Definition

Represents unpaid principal balance of loans purchased.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow resulting from the sale of loans classified as held-for-sale, including proceeds from loans sold through mortgage securitization.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3337-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3461-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfLoansHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pfsi_MortgageBankingServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pfsi_MortgageServicingRightsRecaptureAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pfsi_MortgageLendingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Transactions with Affiliates - Correspondent Production (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
	Sep. 12, 2016	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
MBS Agreement
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.35%
Fulfillment fee as a percent of UPB for mortgage loans sold or delivered to Fannie Mae or Freddie Mac	0.50%
MSR Recapture Agreement
Transactions with Affiliates
Related party transaction, automatic renewal period	18 months
Lending activity between the entity and affiliate
Minimum percent of total UPB of loans originated from refinancing of loans which a related party previously held the MSR required to be transferred	30.00%
PMT
Lending activity between the entity and affiliate
Sale of loans held for sale to PMT										$ 6,255,915	$ 3,343,028	$ 904,097
Fulfillment fee revenue		$ 58,297	$ 45,149	$ 29,590	$ 27,574	$ 28,591	$ 26,256	$ 14,559	$ 11,944	160,610	81,350	80,359
Proceeds from sale of mortgage loans held for sale to PennyMac Mortgage Investment Trust										6,255,915	3,343,028	904,097
PMT \| MBS Agreement \| Minimum
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.02%
PMT \| MBS Agreement \| Maximum
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.035%
PMT \| Loan Lending
Lending activity between the entity and affiliate
Net gain on loans held for sale to PMT										190,416	69,359	28,238
Mortgage servicing rights and excess servicing spread recapture incurred										(7,051)	(4,776)	(6,249)
Total of gain on sale of loans and MSR recapture										183,365	64,583	21,989
Sale of loans held for sale to PMT										6,255,915	3,343,028	904,097
Tax service fee										14,695	7,433	7,078
Fulfillment fee revenue										160,610	81,350	80,359
Unpaid principal balance of loans fulfilled for PMT										56,033,704	26,194,303	22,971,119
Sourcing fees paid										14,381	10,925	12,084
Unpaid principal balance of loans purchased from PMT										47,937,306	36,415,933	40,561,241
Proceeds from sale of mortgage loans held for sale to PennyMac Mortgage Investment Trust										$ 6,255,915	$ 3,343,028	$ 904,097