No definition available.

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

- Definition

The number of days from purchase that fulfillment fees are collected.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The period from quarter end that management fees are collected.

+ References

No definition available.

+ Details

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

- Definition

Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all domestic and foreign income tax obligations due. This amount is the total of current and noncurrent accrued income taxes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15)(1))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: 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(24))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319

Reference 4: 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(20))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(15)(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

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

- Definition

Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

+ Details

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

- Definition

Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4I
-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4590271-111686

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683

+ Details

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

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis=pfsi_AccountingStandardsCodification250MortgageServicingRightsFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Basis of Presentation and Accounting Developments - Mortgage Servicing Rights (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Jan. 02, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Recently Issued Accounting Pronouncements
Mortgage servicing rights	$ 2,785,964,000				$ 2,119,588,000
Income taxes payable	74,158,000				52,160,000
Stockholders' equity	$ 1,916,710,000	$ 1,861,944,000			$ 1,719,674,000	$ 1,590,291,000	$ 1,511,252,000	$ 1,399,356,000
Fulfillment Fees
Number of days from purchase fulfillment fees are collected	30 days
Management fees
The period from quarter end that management fees are collected	30 days
Adjustment \| Accounting Standards Codification 250 Mortgage Servicing Rights Fair Value
Recently Issued Accounting Pronouncements
Mortgage servicing rights				$ 848,000
Income taxes payable			$ 72,000
Stockholders' equity			$ 776,000