Number of common shares held by affiliate.

No definition available.

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Balance Type:	na
Period Type:	instant

- Definition

Represents payments of underwriting fees provided for in the Company's initial public offering payable contingent on the company satisfying certain performance measures over a specified period.

+ References

No definition available.

+ Details

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Namespace Prefix:	pmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Proceeds from sale of excess servicing spread.

+ References

No definition available.

+ Details

Name:	pmt_ProceedsFromTheSaleOfExcessServicingSpread
Namespace Prefix:	pmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(3),(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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Namespace Prefix:	us-gaap_
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://www.xbrl.org/2003/role/presentationRef
-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

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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

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- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Transactions with Related Parties - Note Payable to PLS - Additional Information (Detail) - USD ($)		3 Months Ended
	Aug. 04, 2009	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Apr. 30, 2015
Related Party Transaction [Line Items]
Sale of excess servicing spread		$ 59,045,000	$ 0
Payment of contingent underwriting fees		$ 0	$ 470,000
PennyMac Financial Services, Inc. [Member]
Related Party Transaction [Line Items]
Number of common shares held by affiliate		75,000		75,000
PNMAC Capital Management LLC [Member] \| Maximum [Member]
Related Party Transaction [Line Items]
PMT agreed to reimburse PCM for a payment	$ 2,900,000
Payment of contingent underwriting fees	$ 5,900,000
Loan Agreement [Member]
Related Party Transaction [Line Items]
Maximum borrowing capacity of loan amount					$ 150,000,000