Transactions with Affiliates (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended		8 Months Ended														8 Months Ended		3 Months Ended		8 Months Ended	9 Months Ended		1 Months Ended	8 Months Ended	1 Months Ended	8 Months Ended	1 Months Ended	3 Months Ended		9 Months Ended		8 Months Ended															3 Months Ended	9 Months Ended		8 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013 PMT	Sep. 30, 2012 PMT	Sep. 30, 2013 PMT item	Sep. 30, 2012 PMT	Dec. 31, 2012 PMT	Jan. 31, 2013 PMT Management Fees item	Sep. 30, 2013 PMT Management Fees	Sep. 30, 2012 PMT Management Fees	Sep. 30, 2013 PMT Management Fees item	Sep. 30, 2013 PMT Management Fees	Sep. 30, 2012 PMT Management Fees	Sep. 30, 2013 PMT Management Fees Minimum	Sep. 30, 2013 PMT Management Fees Maximum	Sep. 30, 2013 PMT Management Fees 8% return on equity	Sep. 30, 2013 PMT Management Fees 8% return on equity Minimum	Sep. 30, 2013 PMT Management Fees 8% return on equity Maximum	Sep. 30, 2013 PMT Management Fees 12% return on equity	Sep. 30, 2013 PMT Management Fees 12% return on equity Minimum	Sep. 30, 2013 PMT Management Fees 12% return on equity Maximum	Sep. 30, 2013 PMT Management Fees In excess of 16% return on equity	Sep. 30, 2013 PMT Management Fees In excess of 16% return on equity Maximum	Sep. 30, 2013 PMT Management Fees Shareholders' equity up to $2 billion Maximum	Sep. 30, 2013 PMT Management Fees Shareholders' equity in excess of $2 billion and up to $5 billion	Sep. 30, 2013 PMT Management Fees Shareholders' equity in excess of $2 billion and up to $5 billion Minimum	Sep. 30, 2013 PMT Management Fees Shareholders' equity in excess of $2 billion and up to $5 billion Maximum	Sep. 30, 2013 PMT Management Fees Shareholders' equity in excess of $5 billion	Sep. 30, 2013 PMT Management Fees Shareholders' equity in excess of $5 billion Minimum	Sep. 30, 2013 PMT Mortgage Loan Servicing	Sep. 30, 2012 PMT Mortgage Loan Servicing	Sep. 30, 2013 PMT Mortgage Loan Servicing	Sep. 30, 2013 PMT Mortgage Loan Servicing	Sep. 30, 2012 PMT Mortgage Loan Servicing	Jan. 31, 2013 PMT Mortgage Loan Servicing Minimum	Sep. 30, 2013 PMT Mortgage Loan Servicing Minimum	Jan. 31, 2013 PMT Mortgage Loan Servicing Maximum	Sep. 30, 2013 PMT Mortgage Loan Servicing Maximum	Jan. 31, 2013 PMT Correspondent Lending	Sep. 30, 2013 PMT Correspondent Lending	Sep. 30, 2012 PMT Correspondent Lending	Sep. 30, 2013 PMT Correspondent Lending	Sep. 30, 2012 PMT Correspondent Lending	Sep. 30, 2013 PMT Correspondent Lending Purchases mortgage loans with an aggregate unpaid principal balance in any month greater than $2.5 billion and less than $5 billion	Sep. 30, 2013 PMT Correspondent Lending Purchases mortgage loans with an aggregate unpaid principal balance in any month $5 billion	Sep. 30, 2013 PMT Correspondent Lending Conventional mortgage loans	Sep. 30, 2013 PMT Correspondent Lending Ginnie Mae Mortgage-Backed Securities Guide mortgage loans	Sep. 30, 2013 PMT Correspondent Lending HARP mortgage loans with a loan-to-value ratio of 105% or less	Sep. 30, 2013 PMT Correspondent Lending HARP mortgage loans with a loan-to-value ratio of greater than 105%	Sep. 30, 2013 PMT Correspondent Lending Other mortgage loans	Sep. 30, 2013 PMT Correspondent Lending Minimum Purchases mortgage loans with an aggregate unpaid principal balance in any month greater than $2.5 billion and less than $5 billion	Sep. 30, 2013 PMT Correspondent Lending Minimum Purchases mortgage loans with an aggregate unpaid principal balance in any month $5 billion	Sep. 30, 2013 PMT Correspondent Lending Minimum HARP mortgage loans with a loan-to-value ratio of 105% or less	Sep. 30, 2013 PMT Correspondent Lending Maximum Purchases mortgage loans with an aggregate unpaid principal balance in any month greater than $2.5 billion and less than $5 billion	Sep. 30, 2013 PMT Correspondent Lending Maximum HARP mortgage loans with a loan-to-value ratio of greater than 105%	Sep. 30, 2013 PMT Mortgage banking services	Sep. 30, 2013 PMT Warehouse services	Sep. 30, 2013 PMT Mortgage banking and warehouse services	Sep. 30, 2013 PMT Investment Activities	Sep. 30, 2013 PMT Investment Activities	Jun. 30, 2013 PMT Investment Activities	Sep. 30, 2013 PMT Investment Activities Minimum	Sep. 30, 2013 PMT Conditional Reimbursement	Sep. 30, 2013 PMT Conditional Reimbursement	Sep. 30, 2013 PMT Conditional Reimbursement	Aug. 04, 2009 PMT Conditional Reimbursement	Sep. 30, 2013 PMT Conditional Reimbursement Maximum	Sep. 30, 2013 PCM	Sep. 30, 2012 PCM	Sep. 30, 2013 PCM	Sep. 30, 2012 PCM	Sep. 30, 2013 Investment Funds	Sep. 30, 2012 Investment Funds	Sep. 30, 2013 Investment Funds	Sep. 30, 2012 Investment Funds	Jun. 30, 2013 Investment Funds	Dec. 31, 2012 Investment Funds	Jun. 30, 2012 Investment Funds	Dec. 31, 2011 Investment Funds	Sep. 30, 2013 PNMAC Mortgage Opportunity Fund, LLC	Dec. 31, 2012 PNMAC Mortgage Opportunity Fund, LLC	Sep. 30, 2013 PNMAC Mortgage Opportunity Fund Investors, LLC	Dec. 31, 2012 PNMAC Mortgage Opportunity Fund Investors, LLC
Transactions with Affiliates
Base management fee annual rate (as a percent)											1.50%																1.50%	1.375%			1.25%
Percentage of net income for calculation of performance incentive fees											20.00%								10.00%			15.00%			20.00%
Number of rolling quarters taken as base for performance incentive fee computation											4			4
Hurdle rate (as a percent)											8.00%
High watermark																	$ 0
Percentage of change in net income due to quarterly adjustments														8.00%
Base management fee shareholders' equity limit																											2,000,000,000		2,000,000,000	5,000,000,000		5,000,000,000
Percentage of return on affiliate's equity																				8.00%	12.00%		12.00%	16.00%		16.00%
Percentage of performance incentive fee payable by issuance of common shares																		50.00%
Base management and performance incentive fees earned
Base management fee												5,104,000	3,672,000		14,043,000	7,964,000
Performance incentive fee												3,435,000			9,443,000
Management fees	10,540,000	6,114,000	29,375,000	15,163,000		8,539,000	3,672,000	23,486,000	7,964,000			8,539,000	3,672,000		23,486,000	7,964,000																																																											2,001,000	2,442,000	5,889,000	7,199,000
Multiplier for calculating the termination fee								3
Period for calculating average annual fees								24 months
Renewal period of servicing agreement															18 months																					18 months									18 months																		18 months
Servicing fee rates per year for nonperforming loans (as a percent)																																						0.50%		1.00%
Servicing fees amount per month for current loans																																							30
Servicing fees amount per month for severely delinquent loans																																									125
Base servicing fees per month for fixed-rate non-distressed loans subserviced																																			7.50
Base servicing fees per month for adjustable rate non-distressed loans subserviced																																			8.50
Additional servicing fee amount per month for delinquent loans																																							10		75
Supplemental fee per month for each distressed whole loan																																			25
Supplemental fee per month for each non-distressed subserviced loan																																			3.25
Mortgage loan servicing fees earned
Base																																	7,139,000	3,518,000		19,005,000	9,656,000
Activity-based																																	3,599,000	1,082,000		8,246,000	3,507,000
Loan servicing fees																																	10,738,000	4,600,000		27,251,000	13,163,000
Fulfillment fee as a percentage of unpaid principal balance of mortgage loans sold to non-affiliates																																										0.50%							0.50%	0.88%	0.80%	1.20%	0.50%
Mortgage loans, loan-to-value ratio (as a percent)																																																								105.00%		105.00%
Sourcing fee rate (as a percent)																																																		0.03%
Threshold unpaid principal balance of mortgage loans sold to non-affiliates																																																						2,500,000,000	5,000,000,000		5,000,000,000
Fulfillment fee reimbursement as a percentage of unpaid principal balance of mortgage loans sold to non-affiliates																																															0.025%	0.05%
Threshold unpaid principal balance of mortgage loans sold to non-affiliates for calculation of fulfillment fee																																																						2,500,000,000	5,000,000,000
Mortgage loan servicing fee per year																																																											25,000	25,000	25,000
Mortgage loan servicing fee per loan (in dollars)																																																											50	50	50
Lending activity between the entity and affiliate
Sourcing fees paid																																											1,204,000	747,000	3,563,000	1,448,000
Fulfillment fee revenue						18,327,000	17,258,000	68,625,000	31,097,000																																		18,327,000	17,258,000	68,625,000	31,097,000
Unpaid principal balance of loans fulfilled for PMT																																											3,681,771,000	2,488,443,000	12,792,482,000	4,828,117,000
Fair value of loans purchased from PMT																																											4,147,535,000	2,650,097,000	12,429,698,000	5,111,185,000
Threshold percentage of unpaid principal balance with respect to new mortgage loans originating in refinancing																																																																	30.00%
Fair market value of the aggregate MSRs to be transferred																																																																200,000
Gain on mortgage loans held for sale	25,949,000	39,760,000	108,560,000	68,487,000																																																										86,000	586,000
Amount of tax benefits under the tax receivable agreement (as a percent)			85.00%
Amount of tax liability under the tax sharing agreement	58,600,000		58,600,000
Conditional reimbursement																																																																					2,900,000	2,900,000
Performance incentive fees reimbursement under the management agreement for every $100 of performance incentive fees earned																																																																			10
Maximum performance incentive fees reimbursement within 12-month period																																																																			1,000,000
Payments received																																																																		388,000		601,000
Foregoing reimbursement of expenses
Reimbursement of expenses incurred on behalf of affiliates	4,486,000	1,799,000	12,126,000	4,894,000		1,934,000	555,000	3,767,000	2,420,000																																																														2,552,000	1,244,000	8,359,000	2,474,000
Payments and settlements during the period	29,315,000	12,239,000	94,606,000	28,896,000
Amounts due from affiliate
Management fees						8,539,000		8,539,000		4,473,000																																																																	2,001,000		2,001,000			2,164,000
Servicing fees						5,152,000		5,152,000		3,670,000
Underwriting fees						2,131,000		2,131,000		2,941,000
Allocated expenses						4,208,000		4,208,000		1,132,000
Loan purchases										4,475,000
Loan servicing fees																																																																											47,000		47,000			1,052,000
Loan servicing rebate																																																																											(123,000)		(123,000)			(239,000)
Expense reimbursements																																																																											616,000		616,000			695,000
Total due from affiliate						20,030,000		20,030,000		16,691,000																																																																	2,541,000		2,541,000			3,672,000
Investment in affiliate, common shares of beneficial interest (in shares)						75,000		75,000		75,000
Investment in affiliates, at fair value						1,700,000		1,700,000		1,900,000
Carried Interest due from affiliates	58,134,000		58,134,000		47,723,000																																																																						58,134,000	44,504,000	58,134,000	44,504,000	55,322,000	47,723,000	41,149,000	37,250,000	36,357,000	29,785,000	21,777,000	17,938,000
Amounts due to affiliates						$ 55,523,000		$ 55,523,000		$ 46,779,000																																																																	$ 36,424,000		$ 36,424,000			$ 36,795,000