Significant Accounting Policies (Details)	9 Months Ended
Sep. 30, 2013
Significant Accounting Policies
Amount of cash savings under an agreement (as a percent)	85.00%

Amount of cash tax savings allocated to PennyMac unitholders arising from the tax benefits of the conversion of their units into PFSI shares.

No definition available.

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