PennyMac Mortgage Investment Trust (PMT) 10-Q 7 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 06, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	PMT
Entity Registrant Name	PennyMac Mortgage Investment Trust
Entity Central Index Key	1,464,423
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		60,951,444

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Cash	$ 88,929	$ 77,647
Short-term investments at fair value	26,736	18,398
Mortgage-backed securities at fair value pledged to creditors	2,126,507	989,461
Mortgage loans acquired for sale at fair value (includes $1,930,547 and $1,249,277 pledged to creditors, respectively)	1,949,432	1,269,515
Mortgage loans at fair value (includes $624,267 and $1,081,893 pledged to creditors, respectively)	633,168	1,089,473
Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value pledged to secure Assets sold to PennyMac Financial Services, Inc. under agreements to repurchase	223,275	236,534
Derivative assets (includes $27,710 and $26,058 pledged to creditors, respectively)	143,577	113,881
Firm commitment to purchase credit risk transfer security at fair value	18,749	0
Real estate acquired in settlement of loans (includes $69,399 and $124,532 pledged to creditors, respectively)	95,605	162,865
Real estate held for investment (includes $31,795 and $31,128 pledged to creditors, respectively)	45,971	44,224
Deposits securing credit risk transfer agreements (includes $378,090 and $400,778 pledged to creditors, respectively)	662,624	588,867
Mortgage servicing rights (includes $1,109,741 and $91,459 at fair value; $1,090,406 and $831,892 pledged to creditors)	1,109,741	844,781
Servicing advances	48,056	77,158
Other	92,857	87,975
Total assets	7,267,578	5,604,933
LIABILITIES
Assets sold under agreements to repurchase	4,394,500	3,180,886
Mortgage loan participation purchase and sale agreements	31,578	44,488
Exchangeable senior notes	248,053	247,186
Notes payable	445,318	0
Asset-backed financing of a variable interest entity at fair value	278,113	307,419
Interest-only security payable at fair value	8,821	7,070
Derivative liabilities	11,880	1,306
Accounts payable and accrued liabilities	70,362	64,751
Income taxes payable	52,382	27,317
Liability for losses under representations and warranties	7,413	8,678
Total liabilities	5,709,015	4,060,348
Commitments and contingencies — Note 20	0	0
SHAREHOLDERS’ EQUITY
Preferred shares of beneficial interest, $0.01 par value per share, authorized 100,000,000 shares, issued and outstanding 12,400,000 shares, liquidation preference $310,000,000	299,707	299,707
Common shares of beneficial interest—authorized, 500,000,000 common shares of $0.01 par value; issued and outstanding, 60,951,444 and 61,334,087 common shares, respectively	610	613
Additional paid-in capital	1,284,537	1,290,931
Accumulated deficit	(26,291)	(46,666)
Total shareholders’ equity	1,558,563	1,544,585
Total liabilities and shareholders’ equity	7,267,578	5,604,933
Variable Interest Entities [Member]
ASSETS
Mortgage loans at fair value (includes $624,267 and $1,081,893 pledged to creditors, respectively)	292,174	321,040
Derivative assets (includes $27,710 and $26,058 pledged to creditors, respectively)	126,354	98,640
Deposits securing credit risk transfer agreements (includes $378,090 and $400,778 pledged to creditors, respectively)	662,624	588,867
Other—interest receivable	855	904
Total assets of Consolidated Variable Interest Entity	1,082,007	1,009,451
LIABILITIES
Asset-backed financing of a variable interest entity at fair value	278,113	307,419
Interest-only security payable at fair value	8,821	7,070
Accounts payable and accrued liabilities—interest payable	855	904
SHAREHOLDERS’ EQUITY
Total liabilities of Consolidated Variable Interest Entity	287,789	315,393
PennyMac Financial Services, Inc. [Member]
ASSETS
Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value pledged to secure Assets sold to PennyMac Financial Services, Inc. under agreements to repurchase	223,275	236,534
Due from PennyMac Financial Services, Inc.	2,351	4,154
LIABILITIES
Assets sold under agreements to repurchase	133,128	144,128
Due to PennyMac Financial Services, Inc.	$ 27,467	$ 27,119

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Mortgage loans acquired for sale at fair value, pledged to creditors	$ 1,930,547,000	$ 1,249,277,000
Mortgage loans at fair value, pledged to creditors	624,267,000	1,081,893,000
Derivative assets, pledged to creditors	27,710,000	26,058,000
Real estate pledged to creditors	69,399,000	124,532,000
Deposits securing credit risk transfer agreements, pledged to creditors	378,090,000	400,778,000
Mortgage servicing rights at fair value	1,109,741,000	91,459,000
Mortgage servicing rights pledged to creditors	$ 1,090,406,000	$ 831,892,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	12,400,000	12,400,000
Preferred stock, shares outstanding	12,400,000	12,400,000
Preferred stock, liquidation preference, value	$ 310,000,000	$ 310,000,000
Common shares, authorized	500,000,000	500,000,000
Common shares, par value	$ 0.01	$ 0.01
Common shares, issued	60,951,444	61,334,087
Common shares, outstanding	60,951,444	61,334,087
Real Estate Acquired in Satisfaction of Debt [Member]
Real estate pledged to creditors	$ 69,399,000	$ 124,532,000
Real Estate Held for Investment [Member]
Real estate pledged to creditors	$ 31,795,000	$ 31,128,000

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net investment income
Net mortgage loan servicing fees	$ 44,394	$ 21,876	$ 128,135	$ 49,325
Net gain on mortgage loans acquired for sale	24,810	17,967	41,579	54,284
Mortgage loan origination fees	12,424	11,744	28,311	30,501
Net gain (loss) on investments	9,683	13,834	35,210	58,147
Interest income	62,324	51,577	155,648	152,063
Interest expense:
Interest expense	46,609	40,277	121,490	115,882
Net interest income	15,715	11,300	34,158	36,181
Results of real estate acquired in settlement of loans	(310)	(3,143)	(5,833)	(10,854)
Other	1,785	2,226	5,605	6,653
Net investment income	108,501	75,804	267,165	224,237
Expenses
Mortgage loan fulfillment fees	26,256	23,507	52,759	61,184
Mortgage loan servicing fees	10,071	11,402	30,521	31,987
Management fees	6,482	6,038	17,906	16,684
Mortgage loan collection and liquidation	2,747	864	6,899	4,556
Professional services	2,616	1,331	5,692	5,531
Compensation	1,924	1,067	5,412	4,918
Real estate held for investment	1,713	1,898	4,452	4,339
Mortgage loan origination	2,136	2,230	3,980	5,735
Other	2,894	3,301	7,758	10,704
Total expenses	56,839	51,638	135,379	145,638
Income before provision for income taxes	51,662	24,166	131,786	78,599
Provision for income taxes	5,100	4,771	20,613	1,688
Net income	46,562	19,395	111,173	76,911
Dividends on preferred shares	6,235	6,125	18,703	9,032
Net income attributable to common shareholders	$ 40,327	$ 13,270	$ 92,470	$ 67,879
Earnings per common share
Basic	$ 0.66	$ 0.20	$ 1.51	$ 1.01
Diluted	$ 0.62	$ 0.20	$ 1.44	$ 0.98
Weighted-average common shares outstanding
Basic	60,950	66,636	60,880	66,702
Diluted	69,417	66,636	69,347	75,169
Dividends declared per common share	$ 0.47	$ 0.47	$ 1.41	$ 1.41
Nonaffiliates [Member]
Net investment income
Net mortgage loan servicing fees	$ 43,833	$ 21,543	$ 126,567	$ 48,466
Net gain on mortgage loans acquired for sale	22,121	14,692	33,358	44,944
Net gain (loss) on investments	7,977	17,499	24,233	69,067
Interest income	58,584	47,579	144,064	139,052
Interest expense:
Interest expense	44,797	38,161	115,804	109,936
PennyMac Financial Services, Inc. [Member]
Net investment income
Net mortgage loan servicing fees	561	333	1,568	859
Net gain on mortgage loans acquired for sale	2,689	3,275	8,221	9,340
Net gain (loss) on investments	1,706	(3,665)	10,977	(10,920)
Interest income	3,740	3,998	11,584	13,011
Interest expense:
Interest expense	$ 1,812	$ 2,116	$ 5,686	$ 5,946

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Balance, Amount at Dec. 31, 2016	$ 1,351,114	$ 0	$ 667	$ 1,377,171	$ (26,724)
Balance, Shares at Dec. 31, 2016		0	66,697
Net income	76,911			0	76,911
Share-based compensation, Amount	3,864		$ 3	3,861	0
Share-based compensation, Shares			284
Issuance of preferred shares, Amount	310,000	$ 310,000		0	0
Issuance of preferred shares, Shares		12,400
Issuance costs relating to preferred shares	(10,293)	$ (10,293)		0	0
Dividends:
Common share dividends	(94,477)		$ 0	0	(94,477)
Preferred shares dividends	(7,830)	0	0	0	(7,830)
Repurchase of common shares, Amount	$ (18,724)		$ (11)	(18,713)	0
Repurchase of common shares, Shares	(1,105)		(1,105)
Balance, Amount at Sep. 30, 2017	$ 1,610,565	$ 299,707	$ 659	1,362,319	(52,120)
Balance, Shares at Sep. 30, 2017		12,400	65,876
Balance, Amount at Jun. 30, 2017	1,454,832	$ 111,172	$ 668	1,377,990	(34,998)
Balance, Shares at Jun. 30, 2017		4,600	66,842
Net income	19,395			0	19,395
Share-based compensation, Amount	737		$ 1	736	0
Share-based compensation, Shares			0
Issuance of preferred shares, Amount	195,000	$ 195,000		0	0
Issuance of preferred shares, Shares		7,800
Issuance costs relating to preferred shares	(6,465)	$ (6,465)		0	0
Dividends:
Common share dividends	(31,179)		$ 0	0	(31,179)
Preferred shares dividends	(5,338)	0	0	0	(5,338)
Repurchase of common shares, Amount	$ (16,417)		$ (10)	(16,407)	0
Repurchase of common shares, Shares	(966)		(966)
Balance, Amount at Sep. 30, 2017	$ 1,610,565	$ 299,707	$ 659	1,362,319	(52,120)
Balance, Shares at Sep. 30, 2017		12,400	65,876
Balance, Amount at Dec. 31, 2017	1,544,585	$ 299,707	$ 613	1,290,931	(46,666)
Balance, Shares at Dec. 31, 2017		12,400	61,334
Balance, Shares (Accounting Standards Update 2014-11 Transfers and Servicing [Member]) at Dec. 31, 2017		12,400	61,334
Balance, Amount (Accounting Standards Update 2014-11 Transfers and Servicing [Member]) at Dec. 31, 2017	14,361	$ 0	$ 0	0	14,361
Balance, Amount (Accounting Standards Update 2014-11 Transfers and Servicing [Member]) at Dec. 31, 2017	1,558,946	299,707	613	1,290,931	(32,305)
Net income	111,173			0	111,173
Share-based compensation, Amount	4,322		$ 3	4,319	0
Share-based compensation, Shares			288
Dividends:
Common share dividends	(86,451)	0	$ 0	0	(86,451)
Preferred shares dividends	(18,708)			0	(18,708)
Repurchase of common shares, Amount	$ (10,719)		$ (6)	(10,713)	0
Repurchase of common shares, Shares	(671)		(671)
Balance, Amount at Sep. 30, 2018	$ 1,558,563	$ 299,707	$ 610	1,284,537	(26,291)
Balance, Shares at Sep. 30, 2018		12,400	60,951
Balance, Amount at Jun. 30, 2018	1,545,487	$ 299,707	$ 610	1,282,971	(37,801)
Balance, Shares at Jun. 30, 2018		12,400	60,951
Net income	46,562			0	46,562
Share-based compensation, Amount	1,566		$ 0	1,566	0
Share-based compensation, Shares			0
Dividends:
Common share dividends	(28,816)	$ 0	$ 0	0	(28,816)
Preferred shares dividends	(6,236)			0	(6,236)
Repurchase of common shares, Amount	$ 0
Repurchase of common shares, Shares	0
Balance, Amount at Sep. 30, 2018	$ 1,558,563	$ 299,707	$ 610	$ 1,284,537	$ (26,291)
Balance, Shares at Sep. 30, 2018		12,400	60,951

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Common share dividends declared per share	$ 0.47	$ 0.47	$ 1.41	$ 1.41
Accumulated Deficit [Member]
Common share dividends declared per share	$ 0.47	$ 0.47	$ 1.41	$ 1.41

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net income	$ 111,173	$ 76,911
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Change in fair value, amortization and impairment of mortgage servicing rights, net of hedging results	27,368	75,403
Net gain on mortgage loans acquired for sale at fair value	(41,579)	(54,284)
Net gain on investments	(35,210)	(58,147)
Accrual of interest on excess servicing spread purchased from PennyMac Financial Services, Inc.	(11,584)	(13,011)
Capitalization of interest and fees on mortgage loans at fair value	(6,543)	(27,737)
Amortization of debt issuance (premiums) and costs, net	(3,193)	10,243
Accrual of unearned discounts and amortization of premiums on mortgage-backed securities, mortgage loans at fair value, and asset-backed secured financing of a VIE	2,731	4,625
Results of real estate acquired in settlement of loans	5,833	10,854
Share-based compensation expense	4,322	3,864
Purchase of mortgage loans acquired for sale at fair value from nonaffiliates	(46,127,315)	(49,769,392)
Purchase of mortgage loans acquired for sale at fair value from PennyMac Financial Services, Inc.	(2,336,162)	(373,108)
Repurchase of mortgage loans subject to representation and warranties	(8,243)	(8,706)
Sale and repayment of mortgage loans acquired for sale at fair value to nonaffiliates	18,992,722	17,683,444
Sale of mortgage loans acquired for sale to PennyMac Financial Services, Inc.	28,584,762	32,724,487
Settlement of repurchase agreement derivatives	5,626	0
Decrease in servicing advances	37,506	8,275
Decrease in due from PennyMac Financial Services, Inc.	1,769	2,043
(Increase) decrease in other assets	(31,419)	16,936
Increase (decrease) in accounts payable and accrued liabilities	5,938	(31,155)
Increase (decrease) in due to PennyMac Financial Services, Inc.	348	(454)
Increase in income taxes payable	19,713	1,982
Net cash (used in) provided by operating activities	(801,437)	283,073
Cash flows from investing activities
Net (increase) decrease in short-term investments	(8,338)	116,442
Purchase of mortgage-backed securities at fair value	(1,316,200)	(251,872)
Sale and repayment of mortgage-backed securities at fair value	126,243	85,144
Sale and repayment of mortgage loans at fair value	398,488	345,824
Repayment of excess servicing spread by PennyMac Financial Services, Inc.	35,852	42,320
Net settlement of derivative financial instruments	1,300	(423)
Sale of real estate acquired in settlement of loans	84,645	140,862
Purchase of mortgage servicing rights	0	(79)
Sale of mortgage servicing rights	100	0
Contribution to deposits securing credit risk transfer agreements	(96,446)	(102,146)
Distribution from credit risk transfer agreements	87,596	41,823
Decrease (increase) in margin deposits	4,617	(2,350)
Net cash (used in) provided by investing activities	(682,143)	415,545
Cash flows from financing activities
Sale of assets under agreements to repurchase	60,463,168	58,275,935
Repurchase of assets sold under agreements to repurchase	(59,250,379)	(58,856,728)
Issuance of mortgage loan participation certificates	4,603,429	5,473,935
Repayment of mortgage loan participation certificates	(4,616,304)	(5,455,770)
Advance under notes payable	450,000	135,000
Repayment of notes payable	0	(330,000)
Repayment of asset-backed financing of a variable interest entity at fair value	(16,721)	(42,881)
Sale of assets sold to PennyMac Financial Services, Inc. under agreements to repurchase	2,208	0
Repurchase of assets sold to PennyMac Financial Services, Inc. under agreement to repurchase	(13,208)	(1,928)
Payment of debt issuance costs	(11,125)	(9,342)
Issuance of preferred shares	0	310,000
Payment of issuance costs related to preferred shares	0	(10,293)
Payment of dividends to preferred shareholders	(18,708)	(7,830)
Payment of dividends to common shareholders	(86,779)	(94,953)
Repurchase of common shares	(10,719)	(18,724)
Net cash provided by (used in) financing activities	1,494,862	(633,579)
Net increase in cash and restricted cash	11,282	65,039
Cash and restricted cash at beginning of period	77,647	34,476
Cash and restricted cash at end of period	88,929	99,515
Cash and restricted cash end of period are comprised of the following:
Cash	88,929	99,515
Restricted cash	$ 0	$ 0

Organization

Organization	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Note 1—Organization PennyMac Mortgage Investment Trust (“PMT” or the “Company”) was organized in Maryland on May 18, 2009, and commenced operations on August 4, 2009, when it completed its initial offerings of common shares of beneficial interest (“common shares”). The Company is a specialty finance company, which, through its subsidiaries (all of which are wholly-owned), invests primarily in residential mortgage-related assets. The Company operates in four segments: correspondent production, credit sensitive strategies, interest rate sensitive strategies and corporate: • The correspondent production segment represents the Company’s operations aimed at serving as an intermediary between mortgage lenders and the capital markets by purchasing, pooling and reselling newly originated prime credit quality mortgage loans either directly or in the form of mortgage-backed securities (“MBS”), using the services of PNMAC Capital Management, LLC (“PCM” or the “Manager”) and PennyMac Loan Services, LLC (“PLS”), both indirect controlled subsidiaries of PennyMac Financial Services, Inc. (“PFSI”). • Most of the mortgage loans the Company has acquired in its correspondent production activities have been eligible for sale to government-sponsored entities (“GSEs”) such as the Federal National Mortgage Association (“Fannie Mae”) and the Federal Home Loan Mortgage Corporation (“Freddie Mac”) or through government agencies such as the Government National Mortgage Association (“Ginnie Mae”). Fannie Mae, Freddie Mac and Ginnie Mae are each referred to as an “Agency” and, collectively, as the “Agencies.” • The credit sensitive strategies segment represents the Company’s investments in credit risk transfer agreements (“CRT Agreements”), distressed mortgage loans, real estate acquired in settlement of mortgage loans (“REO”), real estate held for investment, non-Agency subordinated bonds and small balance commercial real estate mortgage loans. • The interest rate sensitive strategies segment represents the Company’s investments in mortgage servicing rights (“MSRs”), excess servicing spread purchased from PFSI (“ESS”), Agency and senior non-Agency MBS and the related interest rate hedging activities. • The corporate segment includes certain interest income, management fee and corporate expense amounts. The Company conducts substantially all of its operations and makes substantially all of its investments through its subsidiary, PennyMac Operating Partnership, L.P. (the “Operating Partnership”), and the Operating Partnership’s subsidiaries. A wholly-owned subsidiary of the Company is the sole general partner, and the Company is the sole limited partner, of the Operating Partnership. The Company believes that it qualifies, and has elected to be taxed, as a real estate investment trust (“REIT”) under the Internal Revenue Code of 1986, as amended, beginning with its taxable period ended on December 31, 2009. To maintain its tax status as a REIT, the Company has to distribute at least 90% of its taxable income in the form of qualifying distributions to shareholders.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Note 2—Basis of Presentation The accompanying consolidated financial statements have been prepared in compliance with accounting principles generally accepted in the United States (“GAAP”) as codified in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification The accompanying unaudited consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, and cash flows for the interim periods, but are not necessarily indicative of the results of operations that may be anticipated for the full year. Intercompany accounts and transactions have been eliminated. Preparation of financial statements in compliance with GAAP requires the Manager to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the reporting period. Actual results will likely differ from those estimates.

Accounting Developments

Accounting Developments	9 Months Ended
	Sep. 30, 2018
Accounting Changes And Error Corrections [Abstract]
Accounting Developments	Note 3—Accounting Developments Accounting Changes Mortgage Servicing Rights Effective January 1, 2018, the Company has elected to change the accounting for the classes of MSRs it accounted for using the amortization method through December 31, 2017, to the fair value method as allowed in the Transfers and Servicing Revenue Recognition As disclosed in Note 33 – Recently Issued Accounting Pronouncements Receivables, Investments and Debt and Equity Securities, Transfers and Servicing, Financial Instruments Derivatives and Hedging . Cash Flows During the nine months ended September 30, 2018, the Company adopted FASB Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230) – Restricted Cash Recently Issued Accounting Pronouncement On June 20, 2018, the FASB issued ASU 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ASU 2018-07 expands the scope of the Compensation—Stock Compensation The Company issues share-based compensation to certain employees of the Manager. Presently, the Company accounts for share-based payments to employees of the Manager under the guidance of Equity – Equity-Based Payments to Non-Employees The amendments in this ASU are effective for the Company for the fiscal year ending December 31, 2019, including interim periods within that fiscal year. Upon adoption, the Manager does not expect to record a cumulative effect adjustment to its accumulated deficit.

Concentration of Risks

Concentration of Risks	9 Months Ended
	Sep. 30, 2018
Risks And Uncertainties [Abstract]
Concentration of Risks	Note 4—Concentration of Risks As discussed in Note 1 — Organization Distressed Mortgage Loans Due to the nature of the Company’s investments in distressed mortgage loans, PMT is exposed, to a greater extent than traditional mortgage investors, to the risks associated with loan performance and resolution, including that borrowers may be in economic distress and/or may have become unemployed, bankrupt or otherwise unable or unwilling to make payments when due, and that fluctuations in the residential real estate market may affect the performance of its investments. Factors influencing these risks include, but are not limited to: • changes in the overall economy, unemployment rates and residential real estate fair values in the markets where the properties securing the Company’s distressed mortgage loans are located; • PCM’s ability to identify and PLS’ ability to execute optimal resolutions of distressed mortgage loans; • the accuracy of valuation information obtained during the Company’s due diligence activities; • PCM’s ability to effectively model, and to develop appropriate model inputs that properly anticipate, future outcomes; • the level of government support for resolution of distressed mortgage loans and the effect of current and future proposed and enacted legislative and regulatory changes on the Company’s ability to effect cures or resolutions to distressed mortgage loans; and • regulatory, judicial and legislative support of the foreclosure process, and the resulting effect on the Company’s ability to acquire and liquidate the real estate securing its portfolio of distressed mortgage loans in a timely manner or at all. Due to these uncertainties, there can be no assurance that risk management activities identified and executed on PMT’s behalf will prevent significant losses arising from the Company’s investments in real estate-related assets. Most of the distressed mortgage loans and REO has been acquired by the Company in prior years from or through one or more subsidiaries of JPMorgan Chase & Co., Citigroup Inc., and Bank of America Corporation, as presented in the following summary: September 30, 2018 December 31, 2017 (in thousands) JPMorgan Chase & Co. Mortgage loans at fair value $ 135,486 $ 315,437 REO 42,003 66,294 177,489 381,731 Citigroup Inc. Mortgage loans at fair value 133,547 280,488 REO 13,223 26,702 146,770 307,190 Bank of America Corporation Mortgage loans at fair value 60,884 143,969 REO 15,786 27,970 76,670 171,939 $ 400,929 $ 860,860 Total carrying value of distressed mortgage loans at fair value and REO $ 436,599 $ 931,298 CRT Agreements As detailed in Note 6 — Loan Sales and Variable Interest Entities The Company’s retention of credit risk through its investment in CRT Agreements subjects it to risks associated with delinquency and foreclosure similar to the risks associated with owning the related mortgage loans, and exposes the Company to risk of loss greater than the risks associated with selling such mortgage loans to Fannie Mae without the retention of such credit risk. Further, under agreements that include Recourse Obligations, the risks associated with delinquency and foreclosure may in some instances be greater than the risks associated with owning the related mortgage loans because the structure of certain of the CRT Agreements provides that the Company may be required to realize losses in the event of delinquency or foreclosure even where there is ultimately no loss realized with respect to such loans (e.g., as a result of a borrower’s re-performance). Beginning in June 2018, the Company entered into a new form of CRT Agreement under which PMT sells pools of recently-originated mortgage loans into Fannie Mae-guaranteed securities and purchases related credit transfer securities that are entitled to receive a portion of the mortgage loans’ interest payments in exchange for absorbing certain losses on such mortgage loans. At the commencement of the aggregation period and before the settlement of the credit-subordinated securities, the Company makes a firm commitment to purchase the securities. Accordingly, the Company recognizes the fair value of such commitment as it sells loans subject to the CRT Agreement, and also recognizes changes in fair value of the firm commitment during the time it is outstanding. Unlike the Company’s investment in CRT Agreements before June 2018, the structure of its investment in credit risk transfer securities only requires the Company to realize losses as the reference mortgage loans realize actual losses. In addition to the risks specific to credit, the Company is exposed to market risk and, as a result of prevailing market conditions or the economy generally, may be required to recognize losses associated with adverse changes to the fair value of the CRT Agreements, the firm commitment to purchase credit risk transfer securities and of the credit risk transfer securities.

Transactions with Related Parti

Transactions with Related Parties	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Transactions with Related Parties	Note 5—Transactions with Related Parties Operating Activities Correspondent Production Activities The Company is provided fulfillment and other services by PLS under an amended and restated mortgage banking services agreement. Pursuant to the terms of the agreement, the monthly fulfillment fee is an amount that shall equal (a) no greater than the product of (i) 0.35% and (ii) the aggregate initial unpaid principal balance (the “Initial UPB”) of all mortgage loans purchased in such month, plus (b) in the case of all mortgage loans other than mortgage loans sold to or securitized through Fannie Mae or Freddie Mac, no greater than the product of (i) 0.50% and (ii) the aggregate Initial UPB of all such mortgage loans sold and securitized in such month; provided however, that no fulfillment fee shall be due or payable to PLS with respect to any mortgage loans underwritten to the Ginnie Mae MBS Guide. The Company does not hold the Ginnie Mae approval required to issue securities guaranteed by Ginnie Mae MBS and act as a servicer. Accordingly, under the agreement, PLS currently purchases loans saleable in accordance with the Ginnie Mae MBS Guide “as is” and without recourse of any kind from the Company at cost less any administrative fees paid by the correspondent to the Company plus accrued interest and a sourcing fee ranging from two to three and one-half basis points, generally based on the average number of calendar days loans are held by the Company prior to purchase by PLS. In consideration for the mortgage banking services provided by PLS with respect to the Company’s acquisition of mortgage loans under PLS’s early purchase program, PLS is entitled to fees accruing (i) at a rate equal to $1,500 per annum per early purchase facility administered by PLS, and (ii) in the amount of $35 for each mortgage loan that the Company acquires. The mortgage banking services agreement expires on September 12, 2020, subject to automatic renewal for additional 18-month periods, unless terminated earlier in accordance with the terms of the agreement. The Company purchases newly originated loans from PLS under a mortgage loan participation purchase and sale agreement and a flow commercial mortgage loan purchase agreement. Historically, the Company has used the mortgage loan participation purchase and sale agreement for the purpose of purchasing from PLS prime jumbo residential mortgage loans. The Company uses the flow commercial mortgage loan purchase agreement for the purpose of purchasing from PLS small balance commercial mortgage loans, including multifamily mortgage loans, originated as part of PLS’s commercial lending activities. Following is a summary of correspondent production activity between the Company and PLS: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Mortgage loans fulfillment fees earned by PLS $ 26,256 $ 23,507 $ 52,759 $ 61,184 Unpaid principal balance ("UPB") of mortgage loans fulfilled by PLS $ 7,517,883 $ 6,530,036 $ 17,139,884 $ 17,079,969 Sourcing fees received from PLS included in Net gain on mortgage loans acquired for sale $ 2,689 $ 3,275 $ 8,221 $ 9,340 UPB of mortgage loans sold to PLS $ 8,916,654 $ 10,915,194 $ 27,404,022 $ 31,131,154 Early purchase program fees paid to PLS included in Mortgage loan servicing fees $ — $ 1 $ — $ 7 Purchases of mortgage loans acquired for sale from PLS $ 908,525 $ 332,886 $ 2,336,162 $ 373,108 Tax service fee paid to PLS included in Other $ 2,119 $ 2,108 $ 4,869 $ 5,377 September 30, 2018 December 31, 2017 (in thousands) Mortgage loans included in Mortgage loans acquired for sale at fair value pending sale to PLS $ 217,334 $ 279,571 Mortgage Loan Servicing Activities The Company, through its Operating Partnership, has an amended and restated mortgage loan servicing agreement with PLS dated as of September 12, 2016. The servicing agreement provides for servicing fees earned by PLS that are based on a percentage of the mortgage loan’s unpaid principal balance or fixed per loan monthly amounts based on the delinquency, bankruptcy and/or foreclosure status of the serviced mortgage loan or the REO. PLS is also entitled to market-based fees and charges including boarding and deboarding fees, liquidation and disposition, assumption, modification and origination fees and a percentage of late charges relating to mortgage loans it services for the Company. • The base servicing fee rates for distressed whole mortgage loans range from $30 per month for current loans up to $100 per month for loans where the borrower has declared bankruptcy. The base servicing fee rate for REO is $75 per month. • To the extent that the Company rents its REO under an REO rental program, the Company pays PLS an REO rental fee of $30 per month per REO, an REO property lease renewal fee of $100 per lease renewal, and a property management fee in an amount equal to PLS’ cost if property management services and/or any related software costs are outsourced to a third-party property management firm or 9% of gross rental income if PLS provides property management services directly. PLS is also entitled to retain any tenant paid application fees and late rent fees and seek reimbursement for certain third party vendor fees. • Except as otherwise provided in the MSR recapture agreement, when PLS effects a refinancing of a mortgage loan on behalf of the Company and not through a third-party lender and the resulting mortgage loan is readily saleable, or PLS originates a loan to facilitate the disposition of an REO, PLS is entitled to receive from the Company market-based fees and compensation consistent with pricing and terms PLS offers unaffiliated parties on a retail basis. • PLS is required to provide a range of services and activities significantly greater in scope than the services provided in connection with a customary servicing arrangement because the Company has limited employees and infrastructure. For these services, PLS received a supplemental fee of $25 per month for each distressed whole loan. PLS is entitled to reimbursement for all customary, good faith reasonable and necessary out-of-pocket expenses incurred in the performance of its servicing obligations. • PLS, on behalf of the Company, is entitled to retain any incentive payments made to it and to which it is entitled under the U.S. Department of Treasury’s Home Affordable Modification Plan (“HAMP”); provided, however, that with respect to any such incentive payments paid to PLS under HAMP in connection with a mortgage loan modification for which the Company previously paid PLS a modification fee, PLS shall reimburse the Company an amount equal to the incentive payments. • PLS is also entitled to certain activity-based fees for distressed whole mortgage loans that are charged based on the achievement of certain events. These fees range from $750 for a streamline modification to $1,750 for a liquidation and $500 for a deed-in-lieu of foreclosure. PLS is not entitled to earn more than one liquidation fee, reperformance fee or modification fee per mortgage loan in any 18-month period. • The base servicing fees for non-distressed mortgage loans subserviced by PLS on the Company’s behalf are also calculated through a monthly per-loan dollar amount, with the actual dollar amount for each loan based on whether the mortgage loan is a fixed-rate or adjustable-rate loan. The base servicing fees for loans subserviced on the Company’s behalf are $7.50 per month for fixed-rate loans and $8.50 per month for adjustable-rate mortgage loans. • To the extent that these non-distressed mortgage loans become delinquent, PLS is entitled to an additional servicing fee per mortgage loan ranging from $10 to $55 per month and based on the delinquency, bankruptcy and foreclosure status of the mortgage loan or $75 per month if the underlying mortgaged property becomes REO. PLS is also entitled to customary ancillary income and certain market-based fees and charges, including boarding and deboarding fees, liquidation and disposition fees, assumption, modification and origination fees. The term of the servicing agreement expires on September 12, 2020, subject to automatic renewal for additional 18-month periods, unless terminated earlier in accordance with the terms of the servicing agreement. Pursuant to the terms of an amended and restated MSR recapture agreement, if PLS refinances mortgage loans for which the Company previously held the MSRs, PLS is generally required to transfer and convey to one of the Company’s wholly-owned subsidiaries cash in an amount equal to 30% of the fair market value of the MSRs related to all the loans so originated. The MSR recapture agreement expires, unless terminated earlier in accordance with the agreement, on September 12, 2020, subject to automatic renewal for additional 18-month periods. Following is a summary of mortgage loan servicing fees earned by PLS and MSR recapture income earned from PLS: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Mortgage loans servicing fees: Mortgage loans acquired for sale at fair value: Base $ 98 $ 88 $ 250 $ 235 Activity-based 218 188 489 507 316 276 739 742 Mortgage loans at fair value: Distressed mortgage loans: Base 614 1,571 2,328 5,284 Activity-based 657 2,702 3,200 6,859 1,271 4,273 5,528 12,143 Mortgage loans held in VIE - Base 35 54 103 96 MSRs: Base 8,291 6,648 23,772 18,631 Activity-based 158 151 379 375 8,449 6,799 24,151 19,006 $ 10,071 $ 11,402 $ 30,521 $ 31,987 Average investment in: Mortgage loans acquired for sale at fair value $ 1,833,232 $ 1,460,054 $ 1,460,547 $ 1,271,158 Mortgage loans at fair value: Distressed mortgage loans $ 417,487 $ 1,104,738 $ 537,300 $ 1,210,328 Mortgage loans held in a VIE $ 299,415 $ 339,464 $ 306,856 $ 350,607 Average MSR portfolio $ 81,350,980 $ 63,584,416 $ 77,522,709 $ 61,764,228 MSR recapture income recognized included in Net mortgage loan servicing fees ‒ Financial Services, Inc. $ 561 $ 333 $ 1,568 $ 859 Management Fees Under a management agreement, the Company pays PCM management fees as follows: • A base management fee that is calculated quarterly and is equal to the sum of (i) 1.5% per year of average shareholders’ equity up to $2 billion, (ii) 1.375% per year of average shareholders’ equity in excess of $2 billion and up to $5 billion, and (iii) 1.25% per year of average shareholders’ equity in excess of $5 billion. • A performance incentive fee that is calculated quarterly at a defined annualized percentage of the amount by which “net income,” on a rolling four-quarter basis and before deducting the incentive fee, exceeds certain levels of return on “equity.” The performance incentive fee is equal to the sum of: (a) 10% of the amount by which “net income” for the quarter exceeds (i) an 8% return on equity plus the high watermark, up to (ii) a 12% return on equity; plus (b) 15% of the amount by which “net income” for the quarter exceeds (i) a 12% return on equity plus the high watermark, up to (ii) a 16% return on equity; plus (c) 20% of the amount by which “net income” for the quarter exceeds a 16% return on equity plus the high watermark. For the purpose of determining the amount of the performance incentive fee: “Net income” is defined as net income or loss attributable to common shares of beneficial interest computed in accordance with GAAP and certain other non-cash charges determined after discussions between PCM and the Company’s independent trustees and after approval by a majority of the Company’s independent trustees. “Equity” is the weighted average of the issue price per common share of all of the Company’s public offerings, multiplied by the weighted average number of common shares outstanding (including restricted share units) in the rolling four-quarter period. The “high watermark” is the quarterly adjustment that reflects the amount by which the “net income” (stated as a percentage of return on equity) in that quarter exceeds or falls short of the lesser of 8% and the average Fannie Mae 30-year MBS yield (the target yield) for the four quarters then ended. The “high watermark” starts at zero and is adjusted quarterly. If the “net income” is lower than the target yield, the high watermark is increased by the difference. If the “net income” is higher than the target yield, the high watermark is reduced by the difference. Each time a performance incentive fee is earned, the high watermark returns to zero. As a result, the threshold amounts required for PCM to earn a performance incentive fee are adjusted cumulatively based on the performance of PMT’s “net income” over (or under) the target yield, until the “net income” in excess of the target yield exceeds the then-current cumulative high watermark amount. The base management fee and the performance incentive fee are both payable quarterly in arrears. The performance incentive fee may be paid in cash or a combination of cash and the Company’s common shares (subject to a limit of no more than 50% paid in common shares), at the Company’s option. The management agreement expires on September 12, 2020, subject to automatic renewal for additional 18-month periods, unless terminated earlier in accordance with the terms of the agreement. In the event of termination of the management agreement between the Company and PCM, PCM may be entitled to a termination fee in certain circumstances. The termination fee is equal to three times the sum of (a) the average annual base management fee, and (b) the average annual performance incentive fee earned by PCM, in each case during the 24-month period immediately preceding the date of termination. Following is a summary of the base management and performance incentive fees payable to PCM recorded by the Company: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Base management $ 5,799 $ 6,038 $ 17,223 $ 16,380 Performance incentive 683 — 683 304 $ 6,482 $ 6,038 $ 17,906 $ 16,684 In the event of termination of the management agreement between the Company and PCM, PCM may be entitled to a termination fee in certain circumstances. The termination fee is equal to three times the sum of (a) the average annual base management fee, and (b) the average annual performance incentive fee earned by PCM, in each case during the 24-month period before termination. Expense Reimbursement and Amounts Payable to and Receivable from PCM Under the management agreement, PCM is entitled to reimbursement of its organizational and operating expenses, including third-party expenses, incurred on the Company’s behalf, it being understood that PCM and its affiliates shall allocate a portion of their personnel’s time to provide certain legal, tax and investor relations services for the direct benefit of the Company. With respect to the allocation of PCM’s and its affiliates’ compensation expenses, from and after September 12, 2016, PCM shall be reimbursed $120,000 per fiscal quarter, such amount to be reviewed annually and to not preclude reimbursement for any other services performed by PCM or its affiliates. The Company is required to pay PCM and its affiliates a portion of rent, telephone, utilities, office furniture, equipment, machinery and other office, internal and overhead expenses of PCM and its affiliates required for the Company’s and its subsidiaries’ operations. These expenses are allocated based on the ratio of the Company’s and its subsidiaries’ proportion of gross assets compared to all remaining gross assets managed by PCM as calculated at each fiscal quarter end. Following is a summary of the Company’s reimbursements to PCM and its affiliates for expenses: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Reimbursement of: Common overhead incurred by PCM and its affiliates $ 1,210 $ 1,193 $ 3,387 $ 4,220 Compensation 120 — 360 — Expenses incurred on the Company’s behalf, net 527 196 586 849 $ 1,857 $ 1,389 $ 4,333 $ 5,069 Payments and settlements during the period (1) $ 21,650 $ 22,786 $ 45,265 $ 63,249 (1) Payments and settlements include payments and netting settlements made pursuant to master netting agreements between the Company and PFSI for the operating, investment and financing activities itemized in this Note. Investing Activities Spread Acquisition and MSR Servicing Agreements On December 19, 2016, the Company, through a wholly-owned subsidiary, PennyMac Holdings, LLC (“PMH”), amended and restated a master spread acquisition and MSR servicing agreement with PLS (the “Spread Acquisition Agreement”), pursuant to which the Company may purchase from PLS, from time to time, the right to receive participation certificates representing beneficial ownership in ESS arising from Ginnie Mae MSRs acquired by PLS, in which case PLS generally would be required to service or subservice the related mortgage loans for Ginnie Mae. The primary purpose of the amendment and restatement was to facilitate the continued financing of the ESS owned by the Company in connection with the parties’ participation in the GNMA MSR Facility (as defined below). To the extent PLS refinances any of the mortgage loans relating to the ESS the Company has acquired, the Spread Acquisition Agreement also contains recapture provisions requiring that PLS transfer to the Company, at no cost, the ESS relating to a certain percentage of the unpaid principal balance of the newly originated mortgage loans. However, under the Spread Acquisition Agreement, in any month where the transferred ESS relating to newly originated Ginnie Mae mortgage loans is not equivalent to at least 90% of the product of the excess servicing fee rate and the unpaid principal balance of the refinanced mortgage loans, PLS is also required to transfer additional ESS or cash in the amount of such shortfall. Similarly, in any month where the transferred ESS relating to modified Ginnie Mae mortgage loans is not equivalent to at least 90% of the product of the excess servicing fee rate and the unpaid principal balance of the modified mortgage loans, the Spread Acquisition Agreement contains provisions that require PLS to transfer additional ESS or cash in the amount of such shortfall. To the extent the fair market value of the aggregate ESS to be transferred for the applicable month is less than $200,000, PLS may, at its option, settle its recapture liability to the Company in cash in an amount equal to such fair market value in lieu of transferring such ESS. Following is a summary of investing activities between the Company and PFSI: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) ESS: Received pursuant to a recapture agreement $ 499 $ 1,207 $ 1,983 $ 4,160 Repayments $ 11,543 $ 13,410 $ 35,852 $ 42,320 Interest income $ 3,740 $ 3,998 $ 11,584 $ 13,011 Net gain (loss) included in Net gain (loss) on investments: Valuation changes $ 1,109 $ (4,828 ) $ 9,026 $ (14,757 ) Recapture income 597 1,163 1,951 3,837 $ 1,706 $ (3,665 ) $ 10,977 $ (10,920 ) September 30, 2018 December 31, 2017 (in thousands) Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value $ 223,275 $ 236,534 Financing Activities PFSI held 75,000 of the Company’s common shares at both September 30, 2018 and December 31, 2017. Repurchase Agreement with PLS On December 19, 2016, the Company, through PMH, entered into a master repurchase agreement with PLS (the “PMH Repurchase Agreement”), pursuant to which PMH may borrow from PLS for the purpose of financing PMH’s participation certificates representing beneficial ownership in ESS acquired from PLS under the Spread Acquisition Agreement. PLS then re-pledges such participation certificates to PNMAC GMSR ISSUER TRUST (the “Issuer Trust”) under a master repurchase agreement by and among PLS, the Issuer Trust and Private National Mortgage Acceptance Company, LLC, as guarantor (the “PC Repurchase Agreement”). The Issuer Trust was formed for the purpose of allowing PLS to finance MSRs and ESS relating to such MSRs (the “GNMA MSR Facility”). In connection with the GNMA MSR Facility, PLS pledges and/or sells to the Issuer Trust participation certificates representing beneficial interests in MSRs and ESS pursuant to the terms of the PC Repurchase Agreement. In return, the Issuer Trust (a) has issued to PLS, pursuant to the terms of an indenture, the Series 2016-MSRVF1 Variable Funding Note, dated December 19, 2016, known as the “PNMAC GMSR ISSUER TRUST MSR Collateralized Notes, Series 2016-MSRVF1” (the “VFN”), and (b) may, from time to time pursuant to the terms of any supplemental indenture, issue to institutional investors additional term notes (“Term Notes”), in each case secured on a pari passu basis by the participation certificates relating to the MSRs and ESS. The maximum principal balance of the VFN is $1 billion. The principal amount paid by PLS for the participation certificates under the PMH Repurchase Agreement is based upon a percentage of the market value of the underlying ESS. Upon PMH’s repurchase of the participation certificates, PMH is required to repay PLS the principal amount relating thereto plus accrued interest (at a rate reflective of the current market and consistent with the weighted average note rate of the VFN and any outstanding Term Notes) to the date of such repurchase. PLS is then required to repay the Issuer Trust the corresponding amount under the PC Repurchase Agreement. Conditional Reimbursement of Initial Public Offering (“IPO”) Underwriting Fees In connection with its IPO, the Company conditionally agreed to reimburse PCM up to $2.9 million for underwriting fees paid to the IPO underwriters by PCM on the Company’s behalf (the “Conditional Reimbursement”). Also in connection with its IPO, the Company agreed to pay the IPO underwriters up to $5.9 million in contingent underwriting fees. There were no reimbursements during the quarter and nine months ended September 30, 2018. The Company reimbursed PCM $30,000 and paid the underwriters $61,000 for the quarter and nine months ended September 30, 2017. During the quarter ended September 30, 2018, the Company incurred performance incentive fees of $683,000. Accordingly, the Company will reimburse PCM $68,000 during the quarter ending December 31, 2018. Following is a summary of financing activities between the Company and PFSI: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Interest expense $ 1,812 $ 2,116 $ 5,686 $ 5,946 Conditional Reimbursements paid to PCM $ — $ 30 $ — $ 30 September 30, 2018 December 31, 2017 (in thousands) Assets sold to PFSI under agreement to repurchase $ 133,128 $ 144,128 Conditional Reimbursement payable to PFSI included in Accounts payable and accrued liabilities $ 870 $ 870 Amounts Receivable from and Payable to PFSI Amounts receivable from and payable to PFSI are summarized below: September 30, 2018 December 31, 2017 (in thousands) Due from PFSI: MSR recapture receivable $ 250 $ 282 Other 2,101 3,872 $ 2,351 $ 4,154 Due to PFSI: Fulfillment fees $ 12,078 $ 346 Management fees 6,482 5,901 Mortgage loan servicing fees 3,765 6,583 Allocated expenses and expenses paid by PFSI on PMT’s behalf 2,295 11,542 Correspondent production fees 1,864 1,735 Conditional Reimbursement 870 870 Interest on Assets sold to PFSI under agreement to repurchase 113 142 $ 27,467 $ 27,119

Loan Sales and Variable Interes

Loan Sales and Variable Interest Entities	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loan Sales and Variable Interest Entities	Note 6—Loan Sales and Variable Interest Entities The Company is a variable interest holder in various special purpose entities that relate to its mortgage loan transfer and, financing activities and credit risk investment. These entities are classified as VIEs for accounting purposes. The Company has distinguished its involvement with VIEs between those VIEs which the Company does not consolidate and those VIEs which the Company consolidates. Unconsolidated VIEs with Continuing Involvement The following table summarizes cash flows between the Company and transferees in transfers of mortgage loans that are accounted for as sales where the Company maintains continuing involvement with the mortgage loans: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Cash flows: Proceeds from sales $ 8,435,791 $ 7,035,994 $ 18,992,722 $ 17,683,444 Mortgage loan servicing fees received (1) $ 49,864 $ 42,237 $ 147,262 $ 119,223 (1) Net of guarantee fees The following table summarizes collection status information for mortgage loans that are accounted for as sales where the Company maintains continuing involvement for the dates presented: September 30, 2018 December 31, 2017 (in thousands) UPB of mortgage loans outstanding $ 83,913,215 $ 71,639,351 UPB of delinquent mortgage loans: 30-89 days delinquent $ 601,114 $ 532,673 90 or more days delinquent: Not in foreclosure $ 140,122 $ 280,786 In foreclosure $ 36,069 $ 25,258 UPB of mortgage loans in bankruptcy $ 66,377 $ 52,202 Custodial funds managed by the Company (1) $ 1,203,229 $ 879,321 (1) Custodial funds include borrower and investor custodial cash accounts relating to mortgage loans serviced under mortgage servicing agreements and are not included on the Company’s consolidated balance sheets. The Company earns placement fees on certain of the custodial funds it manages on behalf of the mortgage loans’ investors, which are included in Interest income Consolidated VIEs Credit Risk Transfer Transactions The Company has entered into mortgage loan sales arrangements pursuant to which it accepts credit risk relating to certain of its mortgage loan sales. These arrangements include CRT Agreements and sales of mortgage loans that include commitments to purchase credit risk transfer securities that absorb credit losses on such mortgage loans. The Company, through PennyMac Corp. (“PMC”), entered into CRT Agreements with Fannie Mae, pursuant to which PMC, through subsidiary trust entities, sells pools of mortgage loans into Fannie Mae-guaranteed securitizations while retaining the Recourse Obligations as part of the retention of an IO ownership interest in such mortgage loans. Transfers of mortgage loans subject to CRT Agreements received sale accounting treatment. The Deposits securing CRT Agreements represent the Company’s maximum contractual exposure to claims under its Recourse Obligations and is the sole source of settlement of losses under the CRT Agreements. Gains and losses on derivatives related to CRT Agreements are included in Net gain (loss) on investments Following is a summary of the CRT Agreements: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) UPB of mortgage loans sold under CRT Agreements $ — $ 4,126,946 $ 5,546,977 $ 9,722,067 Deposits securing CRT Agreements $ 18,558 $ 44,998 $ 96,446 $ 102,146 (Decrease) increase in commitments to fund Deposits securing CRT Agreements resulting from sale of mortgage loans under CRT Agreements $ (18,558 ) $ 108,051 $ 96,037 $ 264,165 Interest earned on Deposits securing Agreements $ 3,190 $ 1,440 $ 8,788 $ 2,703 Gains recognized on CRT Agreements included in Net gain (loss) on investments Realized $ 23,367 $ 10,798 $ 64,907 $ 27,595 Resulting from valuation changes 7,185 4,162 27,714 41,268 30,552 14,960 92,621 68,863 Change in fair value of Interest-only security payable at fair value (3,083 ) 191 (4,105 ) (2,272 ) $ 27,469 $ 15,151 $ 88,516 $ 66,591 Payments made to settle losses $ 443 $ 539 $ 1,452 $ 950 September 30, 2018 December 31, 2017 (in thousands) UPB of mortgage loans subject to credit guarantee obligations $ 30,648,306 $ 26,845,392 Collection status (in UPB): Current $ 30,342,833 $ 26,540,953 30—89 days delinquent $ 226,447 $ 179,144 90—180 days delinquent $ 32,852 $ 101,114 180 or more days delinquent $ 15,520 $ 5,146 Foreclosure $ 9,339 $ 5,463 Bankruptcy $ 21,315 $ 13,572 Carrying value of CRT Agreements: Derivative assets $ 126,354 $ 98,640 Deposits securing CRT agreements $ 662,624 $ 588,867 Interest-only security payable at fair value $ 8,821 $ 7,070 CRT Agreement assets pledged to secure Assets sold under agreements to repurchase : Deposits securing CRT Agreements $ 378,090 $ 400,778 Derivative assets $ 27,710 $ 26,058 Commitments to fund Deposits securing credit risk transfer agreements $ 578,508 $ 482,471 Effective in June 2018, the Company began selling mortgage loans subject to agreements that require the Company to purchase securities that absorb credit losses on such mortgage loans. The Company has elected to account for the firm commitments to purchase such securities at fair value. The Company recognizes these purchase commitments initially as a component of Gain on sale of mortgage loans Net gain (loss) on investments Following is a summary of activity under these purchase commitments during the quarter and nine months ended September 30, 2018: Periods ended September 30, 2018 Quarter Nine months (in thousands) UPB of mortgage loans sold $ 6,773,336 $ 8,308,708 Fair value of firm commitment recognized in Gain on sale of mortgage loans $ 12,311 $ 16,737 Gains recognized on CRT Agreements included in Net gain (loss) on investments $ 2,012 $ 2,012 Increase in face amount of firm commitment to purchase securities backed by mortgage loans sold $ 236,875 $ 294,698 September 30, 2018 (in thousands) Firm commitment to purchase CRT securities $ 294,698 Fair value of firm commitment $ 18,749 UPB of mortgage loans sold subject to firm commitment to purchase securities related to such loans $ 8,097,660 Collection status (in UPB): Current $ 8,073,018 30—89 days delinquent $ 24,439 90—180 days delinquent $ 203 180 or more days delinquent $ — Foreclosure $ — Bankruptcy $ — Jumbo Mortgage Loan Financing On September 30, 2013, the Company completed a securitization transaction in which PMT Loan Trust 2013-J1, a VIE, issued $537.0 million in UPB of certificates backed by fixed-rate prime jumbo mortgage loans, at a 3.9% weighted yield. The fair value of the certificates retained by the Company was $14.1 million and $9.7 million as of September 30, 2018 and December 31, 2017, respectively. The Company includes the balance of certificates issued to nonaffiliates in Asset backed financing of a variable interest entity at fair value

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value	Note 7—Fair Value The Company’s consolidated financial statements include assets and liabilities that are measured based on their fair values. Measurement at fair value may be on a recurring or nonrecurring basis depending on the accounting principles applicable to the specific asset or liability and whether the Manager has elected to carry the item at its fair value as discussed in the following paragraphs. The Company groups its assets and liabilities at fair value in three levels, based on the markets in which the assets and liabilities are traded and the observability of the inputs used to determine fair value. These levels are: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Prices determined or determinable using other significant observable inputs. Observable inputs are inputs that other market participants would use in pricing the asset or liability and are developed based on market data obtained from sources independent of the Company. These may include quoted prices for similar assets or liabilities, interest rates, prepayment speeds, credit risk and other inputs. • Level 3—Prices determined using significant unobservable inputs. In situations where significant observable inputs are unavailable, unobservable inputs may be used. Unobservable inputs reflect the Company’s own judgments about the factors that market participants use in pricing assets and liabilities, and are based on the best information available in the circumstances. • As a result of the difficulty in observing certain significant valuation inputs affecting “Level 3” fair value assets and liabilities, the Manager is required to make judgments regarding these items’ fair values. Different persons in possession of the same facts may reasonably arrive at different conclusions as to the inputs to be applied in valuing these assets and liabilities and to their fair values. Such differences may result in significantly different fair value measurements. Likewise, due to the general illiquidity of some of these assets and liabilities, subsequent transactions may be at values significantly different from those reported. Fair Value Accounting Elections The Manager identified all of the Company’s non-cash financial assets, firm commitment to purchase credit risk transfer securities and MSRs to be accounted for at fair value. The Manager has elected to account for these assets at fair value so such changes in fair value will be reflected in income as they occur and more timely reflect the results of the Company’s performance. Before January 1, 2018, originated MSRs backed by mortgage loans with initial interest rates of less than or equal to 4.5% were accounted for using the amortization method. Beginning January 1, 2018, the Company elected to account for all MSRs at fair value prospectively. The Manager determined that this change makes the accounting treatment for MSRs consistent with lender valuation under financing arrangements and simplifies hedging activities. The Manager has also identified the Company’s asset-backed financing of a VIE and interest only security payable at fair value to be accounted for at fair value to reflect the generally offsetting changes in fair value of these borrowings to changes in fair value of the assets at fair value collateralizing these financings. For other borrowings, the Manager has determined that historical cost accounting is more appropriate because under this method debt issuance costs are amortized over the term of the debt facility, thereby matching the debt issuance cost to the periods benefiting from the availability of the debt. Financial Statement Items Measured at Fair Value on a Recurring Basis Following is a summary of financial statement items that are measured at fair value on a recurring basis: September 30, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets: Short-term investments $ 26,736 $ — $ — $ 26,736 Mortgage-backed securities at fair value — 2,126,507 — 2,126,507 Mortgage loans acquired for sale at fair value — 1,942,335 7,097 1,949,432 Mortgage loans at fair value — 292,174 340,994 633,168 Excess servicing spread purchased from PFSI — — 223,275 223,275 Derivative assets: Interest rate lock commitments — — 2,317 2,317 CRT Agreements — — 126,354 126,354 Repurchase agreement derivatives — — 9,415 9,415 Forward purchase contracts — 1,761 — 1,761 Forward sale contracts — 19,238 — 19,238 MBS call options — 7 — 7 MBS put options — 2,302 — 2,302 Put options on interest rate futures 141 — — 141 Total derivative assets before netting 141 23,308 138,086 161,535 Netting — — — (17,958 ) Total derivative assets after netting 141 23,308 138,086 143,577 Firm commitment to purchase credit risk transfer security at fair value — — 18,749 18,749 Mortgage servicing rights at fair value — — 1,109,741 1,109,741 $ 26,877 $ 4,384,324 $ 1,837,942 $ 6,231,185 Liabilities: Asset-backed financing of a VIE at fair value $ — $ 278,113 $ — $ 278,113 Interest-only security payable at fair value — — 8,821 8,821 Derivative liabilities: Interest rate lock commitments — — 3,418 3,418 Forward purchase contracts — 11,964 — 11,964 Forward sales contracts — 1,719 — 1,719 Total derivative liabilities before netting — 13,683 3,418 17,101 Netting — — — (5,221 ) Total derivative liabilities after netting — 13,683 3,418 11,880 $ — $ 291,796 $ 12,239 $ 298,814 December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Assets: Short-term investments $ 18,398 $ — $ — $ 18,398 Mortgage-backed securities at fair value — 989,461 — 989,461 Mortgage loans acquired for sale at fair value — 1,261,380 8,135 1,269,515 Mortgage loans at fair value — 321,040 768,433 1,089,473 Excess servicing spread purchased from PFSI — — 236,534 236,534 Derivative assets: Interest rate lock commitments — — 4,859 4,859 CRT Agreements — — 98,640 98,640 Repurchase agreement derivatives — — 3,748 3,748 Forward purchase contracts — 4,343 — 4,343 Forward sale contracts — 387 — 387 MBS put options — 3,170 — 3,170 Put options on interest rate futures 656 — — 656 Total derivative assets before netting 656 7,900 107,247 115,803 Netting — — — (1,922 ) Total derivative assets after netting 656 7,900 107,247 113,881 Mortgage servicing rights at fair value — — 91,459 91,459 $ 19,054 $ 2,579,781 $ 1,211,808 $ 3,808,721 Liabilities: Asset-backed financing of a VIE at fair value $ — $ 307,419 $ — $ 307,419 Interest-only security payable at fair value — — 7,070 7,070 Derivative liabilities: Interest rate lock commitments — — 227 227 Forward purchase contracts — 248 — 248 Forward sales contracts — 2,830 — 2,830 Total derivative liabilities before netting — 3,078 227 3,305 Netting — — — (1,999 ) Total derivative liabilities after netting — 3,078 227 1,306 $ — $ 310,497 $ 7,297 $ 315,795 The following is a summary of changes in items measured at fair value on a recurring basis using Level 3 inputs that are significant to the estimation of the fair values of the assets and liabilities at either the beginning or end of the years presented: Quarter ended September 30, 2018 Mortgage loans acquired for sale at fair value Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Firm commitment to purchase CRT security Mortgage servicing rights Total (in thousands) Assets: Balance, June 30, 2018 $ 6,540 $ 447,473 $ 229,470 $ 2,807 $ 119,169 $ 6,912 $ 4,426 $ 1,010,507 $ 1,827,304 Purchases and issuances 2,640 — — (3,699 ) — 5,671 — — 4,612 Repayments and sales (2,481 ) (98,622 ) (11,543 ) — (23,367 ) (3,131 ) — (100 ) (139,244 ) Capitalization of interest — 2,297 3,740 — — — — — 6,037 Capitalization of advances — 1,373 — — — — — — 1,373 ESS received pursuant to a recapture agreement with PFSI — — 499 — — — — — 499 Amounts received as proceeds from sales of mortgage loans — — — — — — 12,311 96,383 108,694 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — 4,407 — — — — — — 4,407 Other factors (324 ) (7,458 ) 1,109 (4,001 ) 30,552 (37 ) 2,012 2,951 24,804 (324 ) (3,051 ) 1,109 (4,001 ) 30,552 (37 ) 2,012 2,951 29,211 Transfers of mortgage loans to REO and real estate held for investment — (8,476 ) — — — — — — (8,476 ) Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2) 722 — — — — — — — 722 Transfers of interest rate lock commitments to mortgage loans acquired for sale — — — 3,792 — — — — 3,792 Balance, September 30, 2018 $ 7,097 $ 340,994 $ 223,275 $ (1,101 ) $ 126,354 $ 9,415 $ 18,749 $ 1,109,741 $ 1,834,524 Changes in fair value recognized during the quarter relating to assets still held at September 30, 2018 $ (257 ) $ (6,711 ) $ 1,109 $ (1,101 ) $ 7,185 $ — $ 2,012 $ 2,951 $ 5,188 (1) For the purpose of this table, the interest rate lock commitment (“IRLC”) asset and liability positions are shown net. (2) During the quarter ended September 30, 2018, the Manager identified certain “Level 2” fair value mortgage loans acquired for sale that were not saleable into the prime mortgage market and therefore transferred them to “Level 3”. Quarter ended September 30, 2018 Interest-only security payable (in thousands) Liabilities: Balance, June 30, 2018 $ 7,652 Changes in fair value included in income arising from: Changes in instrument-specific credit risk — Other factors 1,169 1,169 Balance, September 30, 2018 $ 8,821 Changes in fair value recognized during the quarter relating to liability outstanding at September 30, 2018 $ 1,169 Quarter ended September 30, 2017 Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Mortgage servicing rights Total (in thousands) Assets: Balance, June 30, 2017 $ 1,184,620 $ 261,796 $ 395 $ 52,716 $ — $ 77,624 $ 1,577,151 Purchases and issuances — — 9,264 — 181 10 9,455 Repayments and sales (156,821 ) (13,410 ) — (10,798 ) — — (181,029 ) Capitalization of interest 7,020 3,998 — — — — 11,018 Capitalization of advances 4,611 — — — — — 4,611 ESS received pursuant to a recapture agreement with PFSI — 1,207 — — — — 1,207 Amounts received as proceeds from sales of mortgage loans — — — — — 8,655 8,655 Changes in fair value included in income arising from: Changes in instrument-specific credit risk 6,035 — — — — — 6,035 Other factors (2,758 ) (4,828 ) 15,430 14,960 — (3,977 ) 18,827 3,277 (4,828 ) 15,430 14,960 — (3,977 ) 24,862 Transfers of mortgage loans to REO and real estate held for investment (26,705 ) — — — — — (26,705 ) Transfers of interest rate lock commitments to mortgage loans acquired for sale — — (23,814 ) — — — (23,814 ) Balance, September 30, 2017 $ 1,016,002 $ 248,763 $ 1,275 $ 56,878 $ 181 $ 82,312 $ 1,405,411 Changes in fair value recognized during the quarter relating to assets still held at September 30, 2017 $ (7,302 ) $ (4,828 ) $ 1,275 $ 4,162 $ — $ (3,977 ) $ (10,670 ) (1) For the purpose of this table, the IRLC asset and liability positions are shown net. Quarter ended September 30, 2017 Interest-only security payable (in thousands) Liabilities: Balance, June 30, 2017 $ 6,577 Changes in fair value included in income arising from: Changes in instrument-specific credit risk — Other factors (191 ) (191 ) Balance, September 30, 2017 $ 6,386 Changes in fair value recognized during the quarter relating to liability outstanding at September 30, 2017 $ (191 ) Nine months ended September 30, 2018 Mortgage loans acquired for sale at fair value Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Firm commitment to purchase CRT security Mortgage servicing rights Total (in thousands) Assets: Balance, December 31, 2017 $ 8,135 $ 768,433 $ 236,534 $ 4,632 $ 98,640 $ 3,748 $ — $ 91,459 $ 1,211,581 Cumulative effect of a change in accounting principle — Adoption of fair value accounting for mortgage servicing rights — — — — — — — 773,035 773,035 Balance, January 1, 2018 8,135 768,433 236,534 4,632 98,640 3,748 — 864,494 1,984,616 Purchases and issuances 8,243 — — 2,140 — 11,411 — — 21,794 Repayments and sales (10,441 ) (381,646 ) (35,852 ) — (64,907 ) (5,626 ) — (100 ) (498,572 ) Capitalization of interest — 6,543 11,584 — — — — — 18,127 Capitalization of advances — 4,733 — — — — — — 4,733 ESS received pursuant to a recapture agreement with PFSI — — 1,983 — — — — — 1,983 Amounts received as proceeds from sales of mortgage loans — — — — — — 16,737 228,337 245,074 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — 6,864 — — — — — — 6,864 Other factors (176 ) (24,566 ) 9,026 (28,571 ) 92,621 (118 ) 2,012 17,010 67,238 (176 ) (17,702 ) 9,026 (28,571 ) 92,621 (118 ) 2,012 17,010 74,102 Transfers of mortgage loans to REO and real estate held for investment — (39,367 ) — — — — — — (39,367 ) Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2) 1,336 — — — — — — — 1,336 Transfers of interest rate lock commitments to mortgage loans acquired for sale — — — 20,698 — — — — 20,698 Balance, September 30, 2018 $ 7,097 $ 340,994 $ 223,275 $ (1,101 ) $ 126,354 $ 9,415 $ 18,749 $ 1,109,741 $ 1,834,524 Changes in fair value recognized during the period relating to assets still held at September 30, 2018 $ (330 ) $ (18,170 ) $ 9,026 $ (1,101 ) $ 27,714 $ 77 $ 2,012 $ 17,010 $ 36,238 (1) For the purpose of this table, the IRLC asset and liability positions are shown net. (2) During the nine months ended September 30, 2018, the Manager identified certain “Level 2” fair value mortgage loans acquired for sale that were not saleable into the prime mortgage market and therefore transferred them to “Level 3”. Nine months ended September 30, 2018 Interest-only security payable (in thousands) Liabilities: Balance, December 31, 2017 $ 7,070 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — Other factors 1,751 1,751 Balance, September 30, 2018 $ 8,821 Changes in fair value recognized during the period relating to liability outstanding at September 30, 2018 $ 1,751 Nine months ended September 30, 2017 Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Mortgage servicing rights Total (in thousands) Assets: Balance, December 31, 2016 $ 1,354,572 $ 288,669 $ 3,777 $ 15,610 $ — $ 64,136 $ 1,726,764 Purchases and issuances — — 26,185 — 181 79 26,445 Repayments and sales (302,829 ) (42,320 ) — (27,595 ) — — (372,744 ) Capitalization of interest 27,737 13,011 — — — — 40,748 Capitalization of advances 17,759 — — — — — 17,759 ESS received pursuant to a recapture agreement with PFSI — 4,160 — — — — 4,160 Amounts received as proceeds from sales of mortgage loans — — — — — 28,467 28,467 Changes in fair value included in income arising from: Changes in instrument-specific credit risk 23,498 — — — — — 23,498 Other factors (15,975 ) (14,757 ) 43,946 68,863 — (10,370 ) 71,707 7,523 (14,757 ) 43,946 68,863 — (10,370 ) 95,205 Transfers of mortgage loans to REO and real estate held for investment (88,760 ) — — — — — (88,760 ) Transfers of interest rate lock commitments to mortgage loans acquired for sale — — (72,633 ) — — — (72,633 ) Balance, September 30, 2017 $ 1,016,002 $ 248,763 $ 1,275 $ 56,878 $ 181 $ 82,312 $ 1,405,411 Changes in fair value recognized during the period relating to assets still held at September 30, 2017 $ (6,650 ) $ (14,757 ) $ 1,275 $ 41,268 $ — $ (10,370 ) $ 10,766 (1) For the purpose of this table, the IRLC asset and liability positions are shown net. Nine months ended September 30, 2017 Interest-only security payable (in thousands) Liabilities: Balance, December 31, 2016 $ 4,114 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — Other factors 2,272 2,272 Balance, September 30, 2017 6,386 Changes in fair value recognized during the period relating to liability outstanding at September 30, 2017 $ 2,272 The Company had transfers among the fair value levels arising from transfers of IRLCs to mortgage loans held for sale at fair value upon purchase of the respective mortgage loans. Following are the fair values and related principal amounts due upon maturity of mortgage loans accounted for under the fair value option (including mortgage loans acquired for sale, mortgage loans held in a consolidated VIE, and distressed mortgage loans at fair value): September 30, 2018 December 31, 2017 Fair value Principal amount due upon maturity Difference Fair value Principal amount due upon maturity Difference (in thousands) Mortgage loans acquired for sale at fair value: Current through 89 days delinquent $ 1,949,285 $ 1,900,556 $ 48,729 $ 1,268,121 $ 1,221,125 $ 46,996 90 or more days delinquent: Not in foreclosure 147 187 (40 ) 950 1,120 (170 ) In foreclosure — — — 444 496 (52 ) 147 187 (40 ) 1,394 1,616 (222 ) $ 1,949,432 $ 1,900,743 $ 48,689 $ 1,269,515 $ 1,222,741 $ 46,774 Mortgage loans at fair value: Mortgage loans held in a consolidated VIE: Current through 89 days delinquent $ 292,174 $ 299,843 $ (7,669 ) $ 321,040 $ 316,684 $ 4,356 90 or more days delinquent: Not in foreclosure — — — — — — In foreclosure — — — — — — — — — — — — 292,174 299,843 (7,669 ) 321,040 316,684 4,356 Distressed mortgage loans at fair value: Current through 89 days delinquent 200,176 261,808 (61,632 ) 414,785 519,009 (104,224 ) 90 or more days delinquent: Not in foreclosure 66,791 113,308 (46,517 ) 166,749 257,038 (90,289 ) In foreclosure 74,027 113,067 (39,040 ) 186,899 267,911 (81,012 ) 140,818 226,375 (85,557 ) 353,648 524,949 (171,301 ) 340,994 488,183 (147,189 ) 768,433 1,043,958 (275,525 ) $ 633,168 $ 788,026 $ (154,858 ) $ 1,089,473 $ 1,360,642 $ (271,169 ) Following are the changes in fair value included in current period income by consolidated statement of income line item for financial statement items accounted for under the fair value option: Quarter ended September 30, 2018 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — (19,030 ) (1,229 ) (20,259 ) Mortgage loans acquired for sale at fair value — 751 — — 751 Mortgage loans at fair value — — (6,681 ) 2,458 (4,223 ) ESS at fair value — — 1,109 3,740 4,849 Firm commitment to purchase credit risk transfer security at fair value — 12,311 2,012 — 14,323 MSRs at fair value 2,951 — — — 2,951 $ 2,951 $ 13,062 $ (22,590 ) $ 4,969 $ (1,608 ) Liabilities: Interest-only security payable at fair value $ — $ — $ (1,169 ) $ — $ (1,169 ) Asset-backed financing of a VIE at fair value — — 3,516 (201 ) 3,315 $ — $ — $ 2,347 $ (201 ) $ 2,146 Quarter ended September 30, 2017 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — 5,001 (1,481 ) 3,520 Mortgage loans acquired for sale at fair value — 32,935 — — 32,935 Mortgage loans at fair value — — 5,415 7,617 13,032 ESS at fair value — — (4,828 ) 3,998 (830 ) MSRs at fair value (3,977 ) — — — (3,977 ) $ (3,977 ) $ 32,935 $ 5,588 $ 10,134 $ 44,680 Liabilities: Interest-only security payable at fair value $ — $ — $ 191 $ — $ 191 Asset-backed financing of a VIE at fair value — — (2,158 ) (735 ) (2,893 ) $ — $ — $ (1,967 ) $ (735 ) $ (2,702 ) Nine months ended September 30, 2018 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — (50,288 ) (2,623 ) (52,911 ) Mortgage loans acquired for sale at fair value — (27,397 ) — — (27,397 ) Mortgage loans at fair value — — (29,694 ) 6,509 (23,185 ) ESS at fair value — — 9,026 11,584 20,610 Firm commitment to purchase credit risk transfer security at fair value — 16,737 2,012 — 18,749 MSRs at fair value 17,010 — — — 17,010 $ 17,010 $ (10,660 ) $ (68,944 ) $ 15,470 $ (47,124 ) Liabilities: Interest-only security payable at fair value $ — $ — $ (1,751 ) $ — $ (1,751 ) Asset-backed financing of a VIE at fair value — — 12,658 (74 ) 12,584 $ — $ — $ 10,907 $ (74 ) $ 10,833 Nine months ended September 30, 2017 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — 9,168 (4,276 ) 4,892 Mortgage loans acquired for sale at fair value — 83,839 — — 83,839 Mortgage loans at fair value — — 13,832 29,195 43,027 ESS at fair value — — (14,757 ) 13,011 (1,746 ) MSRs at fair value (10,370 ) — — — (10,370 ) $ (10,370 ) $ 83,839 $ 8,243 $ 37,930 $ 119,642 Liabilities: Interest-only security payable at fair value $ — $ — $ (2,272 ) $ — $ (2,272 ) Asset-backed financing of a VIE at fair value — — (5,581 ) (1,807 ) (7,388 ) $ — $ — $ (7,853 ) $ (1,807 ) $ (9,660 ) Financial Statement Items Measured at Fair Value on a Nonrecurring Basis Following is a summary of the carrying value at year end for financial statement items that were re-measured at fair value on a nonrecurring basis during the periods presented: September 30, 2018 Level 1 Level 2 Level 3 Total (in thousands) Real estate acquired in settlement of loans $ — $ — $ 37,722 $ 37,722 $ — $ — $ 37,722 $ 37,722 December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Real estate acquired in settlement of loans $ — $ — $ 71,380 $ 71,380 MSRs at lower of amortized cost or fair value — — 312,995 312,995 $ — $ — $ 384,375 $ 384,375 The following table summarizes the fair value changes recognized during the period on assets held at period end that were remeasured at fair value on a nonrecurring basis: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Real estate asset acquired in settlement of loans $ (2,285 ) $ (5,666 ) $ (6,209 ) $ (7,454 ) MSRs at lower of amortized cost or fair value — (1,702 ) — (4,287 ) $ (2,285 ) $ (7,368 ) $ (6,209 ) $ (11,741 ) Real Estate Acquired in Settlement of Loans The Company evaluates its REO for impairment with reference to the respective properties’ fair values less cost to sell. The initial carrying value of the REO is measured at cost as indicated by the purchase price in the case of purchased REO or as measured by the fair value of the mortgage loan immediately before REO acquisition in the case of acquisition in settlement of a mortgage loan. REO may be subsequently revalued due to the Company receiving greater access to the property, the property being held for an extended period or receiving indications that the property’s fair value may not be supported by developing market conditions. Any subsequent change in fair value to a level that is less than or equal to the property’s cost is recognized in Results of real estate acquired in settlement of loans Mortgage Servicing Rights at Lower of Amortized Cost or Fair Value Before the Company adopted fair value accounting for all of its existing classes of MSRs on January 1, 2018, the Manager evaluated the Company’s MSRs at lower of amortized cost or fair value for impairment with reference to the asset’s fair value. For purposes of performing its MSR impairment evaluation, the Company stratified its MSRs at lower of amortized cost or fair value based on the interest rates borne by the mortgage loans underlying the MSRs. Mortgage loans were grouped into pools with 50 basis point interest rate ranges for fixed-rate mortgage loans with interest rates between 3.0% and 4.5% and a single pool for mortgage loans with interest rates below 3.0%. MSRs relating to adjustable rate mortgage loans with initial interest rates of 4.5% or less were evaluated in a single pool. If the fair value of MSRs in any of the interest rate pools was below the amortized cost of the MSRs, those MSRs were impaired. When MSRs were impaired, the change in impairment was recognized in current-period income and the carrying value of the MSRs was adjusted using a valuation allowance. If the fair value of the MSRs subsequently increased, the increase in fair value was recognized in current period income only to the extent of the valuation allowance for the respective impairment stratum. The Manager periodically reviewed the various impairment strata to determine whether the fair value of the impaired MSRs in a given stratum was likely to recover. When the Manager deemed recovery of fair value to be unlikely in the foreseeable future, a write-down of the cost of the MSRs for that stratum to its estimated recoverable value was charged to the valuation allowance. Fair Value of Financial Instruments Carried at Amortized Cost Most of the Company’s borrowings are carried at amortized cost. The Company’s Assets sold under agreements to repurchase Mortgage loan participation purchase and sale agreements Exchangeable senior notes, Notes payable Assets sold to PennyMac Financial Services, Inc. under agreements to repurchase The Manager has concluded that the fair values of Assets sold under agreements to repurchase Mortgage loan participation purchase and sale agreements, Notes payable, Assets sold to PennyMac Financial Services, Inc. under agreements to repurchase Exchangeable senior notes Exchangeable senior notes Valuation Governance Most of the Company’s assets, its Asset-backed financing of a VIE, Interest-only security payable Derivative liabilities Due to the difficulty in estimating the fair values of “Level 3” fair value assets and liabilities, the Manager has assigned responsibility for estimating fair value of these assets and liabilities to specialized staff and subjects the valuation process to significant executive management oversight. The Manager’s Financial Analysis and Valuation group (the “FAV group”) is responsible for estimating the fair values of “Level 3” fair value assets and liabilities other than IRLCs and maintaining its valuation policies and procedures. With respect to the non-IRLC “Level 3” valuations, the FAV group reports to the Company’s senior management valuation committee, which oversees the valuations. The FAV group monitors the models used for valuation of the Company’s “Level 3” fair value assets and liabilities, including the models’ performance versus actual results, and reports those results to the Company’s senior management valuation committee. The Company’s senior management valuation committee includes the Company’s executive chairman, chief executive, chief financial, chief risk and deputy chief financial officers. The FAV group is responsible for reporting to the Manager’s valuation committee on the changes in the valuation of the non-IRLC “Level 3” fair value assets and liabilities, including major factors affecting the valuation and any changes in model methods and inputs. To assess the reasonableness of its valuations, the FAV group presents an analysis of the effect on the valuation of changes to the significant inputs to the models. The fair value of the Company’s IRLCs is developed by the Manager’s Capital Markets Risk Management staff and is reviewed by the Manager’s Capital Markets Operations group. Valuation Techniques and Inputs The following is a description of the techniques and inputs used in estimating the fair values of “Level 2” and “Level 3” fair value assets and liabilities: Mortgage-Backed Securities The Company categorizes its current holdings of MBS as “Level 2” fair value assets. Fair value of these MBS is established based on quoted market prices for the Company’s MBS holdings or similar securities. Changes in the fair value of MBS are included in Net gain (loss) on investments Mortgage Loans Fair value of mortgage loans is estimated based on whether the mortgage loans are saleable into active markets: • Mortgage loans that are saleable into active markets, comprised of most of the Company’s mortgage loans acquired for sale at fair value and all of the mortgage loans at fair value held in a VIE, are categorized as “Level 2” fair value assets. The fair values of mortgage loans acquired for sale at fair value are established using their quoted market or contracted price or market price equivalent. For the mortgage loans at fair value held in a VIE, the quoted fair values of all of the individual securities issued by the securitization trust are used to derive a fair value for the mortgage loans. The Company obtains indications of fair value from nonaffiliated brokers based on comparable securities and validates the brokers’ indications of fair value using pricing models and inputs the Manager believes are similar to the models and inputs used by other market participants. • Mortgage loans that are not saleable into active markets, comprised primarily of distressed mortgage loans, are categorized as “Level 3” fair value assets and their fair values are estimated using a discounted cash flow approach. Inputs to the discounted cash flow model include current interest rates, loan amount, payment status, property type, discount rates and forecasts of future interest rates, home prices, prepayment speeds, default speeds, loss severities or contracted selling price when applicable. The valuation process for “Level 3” fair value mortgage loans includes the computation by stratum of the mortgage loans’ fair values and a review for reasonableness of various measures such as weighted average life, projected prepayment and default speeds, and projected default and loss percentages. The FAV group computes the effect on the valuation of changes in inputs such as interest rates, home prices, and delinquency status to assess the reasonableness of changes in the mortgage loan valuation. Changes in fair value attributable to changes in instrument-specific credit risk are measured by the effect on fair value of the change in the respective mortgage loan’s delinquency status and performance history at period-end from the later of the beginning of the period or acquisition date. The significant unobservable inputs used in the fair value measurement of the Company’s mortgage loans at fair value are discount rate, home price projections, voluntary prepayment speeds and default speeds. Significant changes in any of those inputs in isolation could result in a significant change to the mortgage loans’ fair value measurement. Increases in home price projections are generally accompanied by an increase in voluntary prepayment speeds. Changes in the fair value of mortgage loans at fair value are included in Net gain (loss) on investments Following is a quantitative summary of key inputs used in the valuation of the Company’s “Level 3” mortgage loans at fair value: Key inputs (1) September 30, 2018 December 31, 2017 Discount rate Range 2.8% – 16.7% 2.9% – 15.0% Weighted average 7.3% 6.9% Twelve-month projected housing price index change Range 3.5% – 4.4% 3.6% – 4.6% Weighted average 4.1% 4.4% Prepayment speed (2) Range 2.5% – 8.1% 3.2% – 11.0% Weighted average 4.1% 4.2% Total prepayment speed (3) Range 10.4% – 22.3% 10.8% – 23.8% Weighted average 15.6% 16.5% (1) Weighted-average inputs are based on fair value amounts of the mortgage loans. (2) Prepayment speed is measured using Life Voluntary Conditional Prepayment Rate (“CPR”). (3) Total prepayment speed is measured using Life Total CPR. Excess Servicing Spread Purchased from PFSI The Company categorizes ESS as a “Level 3” fair value asset. The Company uses a discounted cash flow approach to estimate the fair value of ESS. The key inputs used in the estimation of the fair value of ESS include pricing spread (discount rate) and prepayment speed. Significant changes to those inputs in isolation may result in a significant change in the ESS fair value measurement. Changes in these key inputs are not necessarily directly related. Changes in the fair value of ESS are included in Net gain (loss) on investments in the consolidated statements of income. Following are the key inputs used in determining the fair value of ESS: Key inputs (1) September 30, 2018 December 31, 2017 UPB of underlying mortgage loans (in thousands) $ 24,058,366 $ 27,217,199 Average servicing fee rate (in basis points) 34 34 Average ESS rate (in basis points) 19 19 Pricing spread (2) Range 3.4% - 3.9% 3.8% - 4.3% Weighted average 3.7% 4.1% Annual total prepayment speed (3) R

Mortgage Backed Securities

Mortgage Backed Securities	9 Months Ended
	Sep. 30, 2018
Mortgage Backed Securities [Abstract]
Mortgage Backed Securities	Note 8—Mortgage Backed Securities Following is a summary of MBS: September 30, 2018 December 31, 2017 Principal balance Net premiums Accumulated valuation changes Fair value Principal balance Net premiums Accumulated valuation changes Fair value (in thousands) Agency: (1) Fannie Mae $ 1,592,192 $ 40,413 $ (46,691 ) $ 1,585,914 $ 774,473 $ 30,355 $ (7,975 ) $ 796,853 Freddie Mac 543,239 6,963 (9,609 ) 540,593 187,127 3,518 1,963 192,608 $ 2,135,431 $ 47,376 $ (56,300 ) $ 2,126,507 $ 961,600 $ 33,873 $ (6,012 ) $ 989,461 (1) All MBS are fixed-rate pass-through securities. All MBS are pledged to secure Assets sold under agreements to repurchase

Mortgage Loans Acquired for Sal

Mortgage Loans Acquired for Sale at Fair Value	9 Months Ended
	Sep. 30, 2018
Mortgage Loans On Real Estate [Abstract]
Mortgage Loans Acquired for Sale at Fair Value	Note 9—Mortgage Loans Acquired for Sale at Fair Value Mortgage loans acquired for sale at fair value is comprised of recently originated mortgage loans purchased by the Company for resale. Following is a summary of the distribution of the Company’s mortgage loans acquired for sale at fair value: Loan type September 30, 2018 December 31, 2017 (in thousands) Agency-eligible $ 1,708,928 $ 971,910 Held for sale to PLS — Government insured or guaranteed 217,334 279,571 Commercial real estate 8,500 9,898 Jumbo 7,573 — Repurchased pursuant to representations and warranties 7,097 8,136 $ 1,949,432 $ 1,269,515 Mortgage loans pledged to secure: Assets sold under agreements to repurchase $ 1,898,155 $ 1,201,992 Mortgage loan participation purchase and sale agreements 32,392 47,285 $ 1,930,547 $ 1,249,277 The Company is not approved by Ginnie Mae as an issuer of Ginnie Mae-guaranteed securities which are backed by government-insured or guaranteed mortgage loans. The Company transfers government-insured or guaranteed mortgage loans that it purchases from correspondent sellers to PLS, which is a Ginnie Mae-approved issuer, and earns a sourcing fee ranging from two to three and one-half basis points, generally based on the average number of calendar days that mortgage loans are held prior to purchase by PLS

Mortgage Loans at Fair Value

Mortgage Loans at Fair Value	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Mortgage Loans at Fair Value	Note 10—Mortgage Loans at Fair Value Mortgage loans at fair value are comprised of mortgage loans that are not acquired for sale and, to the extent they are not held in a VIE securing an asset-backed financing, may be sold at a later date pursuant to the Manager’s determination that such a sale represents the most advantageous disposition strategy for the identified mortgage loan. Following is a summary of the distribution of the Company’s mortgage loans at fair value: September 30, 2018 December 31, 2017 Loan type Fair value Unpaid principal balance Fair value Unpaid principal balance (in thousands) Distressed mortgage loans: Nonperforming mortgage loans $ 140,818 $ 226,375 $ 353,648 $ 524,949 Performing mortgage loans: Interest rate step-up 125,063 170,066 189,724 242,335 Fixed interest rate 58,179 73,769 186,929 236,840 Adjustable-rate/hybrid 16,934 17,973 38,132 39,834 200,176 261,808 414,785 519,009 340,994 488,183 768,433 1,043,958 Fixed interest rate jumbo mortgage loans held in a VIE 292,174 299,843 321,040 316,684 $ 633,168 $ 788,026 $ 1,089,473 $ 1,360,642 Mortgage loans at fair value pledged to secure: Assets sold under agreements to repurchase $ 332,093 $ 760,853 Asset-backed financing of a VIE at fair value 292,174 321,040 $ 624,267 $ 1,081,893 Following is a summary of certain concentrations of credit risk in the portfolio of distressed mortgage loans at fair value: Concentration September 30, 2018 December 31, 2017 (percentages are of fair value) Portion of mortgage loans originated between 2005 and 2007 71% 73% Mortgage loans with unpaid-principal balance-to-current -property-value in excess of 100% 31% 38% States contributing 5% or more of mortgage loans New York California Florida New Jersey New York California New Jersey Florida Massachusetts

Derivative Activities

Derivative Activities	9 Months Ended
	Sep. 30, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Activities	Note 11—Derivative Activities The Company holds and issues derivative financial instruments in connection with its operating activities. Derivative financial instruments are created as a result of certain of the Company’s operations and the Company also enters into derivative transactions as part of its interest rate risk management activities. Derivative financial instruments created as a result of the Company’s operations include: • IRLCs that are created when the Company commits to purchase mortgage loans acquired for sale; • CRT Agreements whereby the Company retains a Recourse Obligation relating to certain mortgage loans it sells into Fannie Mae guaranteed securitizations as part of the retention of an IO ownership interest in such mortgage loans; and • Derivatives that are embedded in a master repurchase agreement that provides for the Company to receive interest expense offsets if it finances mortgage loans approved as satisfying certain consumer credit relief characteristics under the master repurchase agreement. The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier by the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity. The Company engages in interest rate risk management activities in an effort to reduce the variability of earnings caused by the effects of changes in interest rates on the fair value of certain of its assets and liabilities. The Company is exposed to price risk relative to the IRLCs it issues to correspondent sellers and to the mortgage loans it purchases as a result of issuing the IRLCs. The Company bears price risk from the time an IRLC is issued to a correspondent seller until the time the purchased mortgage loan is sold. The Company is exposed to loss if market mortgage interest rates increase, because market interest rate increases generally cause the fair value of the IRLC or mortgage loan acquired for sale to decrease. The Company is exposed to losses related to its investment in MSRs if market mortgage interest rates decrease, because market mortgage interest rate decreases generally encourage mortgage refinancing activity, which reduces the expected life of the mortgage loans underlying the MSRs, causing the fair value of MSRs to decrease. To manage the price risk resulting from interest rate risk, the Company uses derivative financial instruments with the intention of moderating the risk that changes in market interest rates will result in unfavorable changes in the fair value of the Company’s inventory of mortgage loans acquired for sale, mortgage loans held in a VIE, IRLCs, MSRs and MBS financing. The Company records all derivative financial instruments at fair value and records changes in fair value in current period income. Derivative Notional Amounts and Fair Value of Derivatives The Company had the following derivative assets and liabilities recorded within Derivative assets Derivative liabilities Other September 30, 2018 December 31, 2017 Fair value Fair value Notional Derivative Derivative Notional Derivative Derivative Instrument amount assets liabilities amount assets liabilities (in thousands) Derivatives not designated as hedging instruments: Not subject to master netting arrangements: Interest rate lock commitments 1,682,007 $ 2,317 $ 3,418 1,250,803 $ 4,859 $ 227 CRT Agreements 30,648,306 126,354 — 26,845,392 98,640 — Repurchase agreement derivatives 9,415 — 3,748 — Subject to master netting agreements ─ for hedging purposes: Forward purchase contracts 3,350,125 1,761 11,964 1,996,235 4,343 248 Forward sale contracts 5,124,927 19,238 1,719 2,565,271 387 2,830 MBS put options 2,600,000 2,302 — 2,375,000 3,170 — MBS call options 750,000 7 — — — — Put options on interest rate futures 100,000 141 — 550,000 656 — Swap futures — — — 275,000 — — Bond futures 815,000 — — — — — Eurodollar future sale contracts 30,000 — — 937,000 — — Total derivative instruments before netting 161,535 17,101 115,803 3,305 Netting (17,958 ) (5,221 ) (1,922 ) (1,999 ) $ 143,577 $ 11,880 $ 113,881 $ 1,306 Margin deposits placed with (from) derivatives counterparties included in Other $ (12,736 ) $ 76 Derivative assets pledged to secure Assets sold under agreements to repurchase $ 27,710 $ 26,058 The following tables summarize the notional amount activity for derivative contracts used to hedge the Company’s MBS financing, inventory of mortgage loans acquired for sale, mortgage loans at fair value held in a VIE, IRLCs and MSRs. Quarter ended September 30, 2018 Amount, Amount, beginning Dispositions/ end Instrument of quarter Additions expirations of quarter (in thousands) Forward purchase contracts 2,628,934 26,864,290 (26,143,099 ) 3,350,125 Forward sales contracts 3,793,355 36,205,542 (34,873,970 ) 5,124,927 MBS put options 1,550,000 1,050,000 — 2,600,000 MBS call options — 750,000 — 750,000 Call options on interest rate futures 50,000 200,000 (250,000 ) — Put options on interest rate futures 600,000 1,300,000 (1,800,000 ) 100,000 Bond futures 815,000 2,205,000 (2,205,000 ) 815,000 Eurodollar future sale contracts 35,000 5,000 (10,000 ) 30,000 Quarter ended September 30, 2017 Amount, Amount, beginning Dispositions/ end Instrument of quarter Additions expirations of quarter (in thousands) Forward purchase contracts 1,933,390 20,560,886 (20,895,864 ) 1,598,412 Forward sales contracts 3,644,636 27,214,513 (28,050,302 ) 2,808,847 MBS put options 1,475,000 3,200,000 (3,550,000 ) 1,125,000 MBS call options 200,000 275,000 (400,000 ) 75,000 Call options on interest rate futures 200,000 450,000 (400,000 ) 250,000 Put options on interest rate futures 925,000 2,500,000 (2,950,000 ) 475,000 Swap futures 175,000 100,000 — 275,000 Eurodollar future sale contracts 1,139,000 202,000 (303,000 ) 1,038,000 Treasury future buy contracts — 55,000 (55,000 ) — Treasury future sale contracts — 55,000 (55,000 ) — Nine months ended September 30, 2018 Amount, Amount, beginning Dispositions/ end Instrument of period Additions expirations of period (in thousands) Forward purchase contracts 1,996,235 67,406,528 (66,052,638 ) 3,350,125 Forward sales contracts 2,565,271 88,131,417 (85,571,761 ) 5,124,927 MBS put options 2,375,000 9,625,000 (9,400,000 ) 2,600,000 MBS call options — 750,000 — 750,000 Call options on interest rate futures — 525,000 (525,000 ) — Put options on interest rate futures 550,000 11,700,000 (12,150,000 ) 100,000 Swap futures 275,000 — (275,000 ) — Bond futures — 3,020,000 (2,205,000 ) 815,000 Eurodollar future sale contracts 937,000 119,597 (1,026,597 ) 30,000 Nine months ended September 30, 2017 Amount, Amount, beginning Dispositions/ end Instrument of period Additions expirations of period (in thousands) Forward purchase contracts 4,840,707 54,953,063 (58,195,358 ) 1,598,412 Forward sales contracts 6,148,242 73,030,446 (76,369,841 ) 2,808,847 MBS put options 925,000 5,125,000 (4,925,000 ) 1,125,000 MBS call option 750,000 475,000 (1,150,000 ) 75,000 Call options on interest rate futures 200,000 575,000 (525,000 ) 250,000 Put options on interest rate futures 550,000 5,875,000 (5,950,000 ) 475,000 Swap futures 150,000 950,000 (825,000 ) 275,000 Eurodollar future sale contracts 1,351,000 303,000 (616,000 ) 1,038,000 Treasury future buy contracts — 110,700 (110,700 ) — Treasury future sale contracts — 110,700 (110,700 ) — Netting of Financial Instruments The Company has elected to net derivative asset and liability positions, and cash collateral placed with or received from its counterparties when subject to a legally enforceable master netting arrangement. The derivative financial instruments that are not subject to master netting arrangements are IRLCs, CRT Agreement derivatives and repurchase agreement derivatives. As of September 30, 2018 and December 31, 2017, the Company did not enter into reverse repurchase agreements or securities lending transactions that are required to be disclosed in the following tables. Offsetting of Derivative Assets Following is a summary of net derivative assets: September 30, 2018 December 31, 2017 Gross amounts of recognized assets Gross amounts offset in the consolidated balance sheet Net amounts of assets presented in the consolidated balance sheet Gross amounts of recognized assets Gross amounts offset in the consolidated balance sheet Net amounts of assets presented in the consolidated balance sheet (in thousands) Derivative assets: Not subject to master netting arrangements: Interest rate lock commitments $ 2,317 $ — $ 2,317 $ 4,859 $ — $ 4,859 CRT Agreement derivatives 126,354 — 126,354 98,640 — 98,640 Repurchase agreement derivatives 9,415 — 9,415 3,748 — 3,748 138,086 — 138,086 107,247 — 107,247 Subject to master netting arrangements: Forward purchase contracts 1,761 — 1,761 4,343 — 4,343 Forward sale contracts 19,238 — 19,238 387 — 387 MBS call options 7 — 7 — — — MBS put options 2,302 — 2,302 3,170 — 3,170 Put options on interest rate futures 141 — 141 656 — 656 Netting — (17,958 ) (17,958 ) — (1,922 ) (1,922 ) 23,449 (17,958 ) 5,491 8,556 (1,922 ) 6,634 $ 161,535 $ (17,958 ) $ 143,577 $ 115,803 $ (1,922 ) $ 113,881 Derivative Assets, Financial Instruments and Collateral Held by Counterparty The following table summarizes by significant counterparty the amount of derivative asset positions after considering master netting arrangements and financial instruments or cash pledged that do not meet the accounting guidance qualifying for setoff accounting: September 30, 2018 December 31, 2017 Net amount of assets presented in the Gross amounts not offset in the consolidated balance sheet Net amount of assets presented in the Gross amounts not offset in the consolidated balance sheet consolidated balance sheet Financial instruments Cash collateral received Net amount consolidated balance sheet Financial instruments Cash collateral received Net amount (in thousands) CRT Agreements $ 126,354 $ — $ — $ 126,354 $ 98,640 $ — $ — $ 98,640 Interest rate lock commitments 2,317 — — 2,317 4,859 — — 4,859 Deutsche Bank Securities LLC 9,415 — — 9,415 3,748 — — 3,748 Citigroup Global Markets Inc. 2,116 — — 2,116 429 — — 429 Wells Fargo Securities, LLC 950 — — 950 146 — — 146 J.P. Morgan Securities LLC 637 — — 637 2,020 — — 2,020 Bank of America, N.A. 627 — — 627 — — — — Goldman Sachs 558 — — 558 — — — — RJ O’Brien & Associates, LLC 141 — — 141 656 — — 656 Federal National Mortgage Association 9 — — 9 1,606 — — 1,606 Credit Suisse Securities (USA) LLC — — — — 809 — — 809 Morgan Stanley & Co. LLC — — — — 457 — — 457 Other 453 — — 453 511 — — 511 $ 143,577 $ — $ — $ 143,577 $ 113,881 $ — $ — $ 113,881 Offsetting of Derivative Liabilities and Financial Liabilities Following is a summary of net derivative liabilities and assets sold under agreements to repurchase. Assets sold under agreements to repurchase do not qualify for setoff accounting. September 30, 2018 December 31, 2017 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheet Net amounts of liabilities presented in the consolidated balance sheet Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheet Net amounts of liabilities presented in the consolidated balance sheet (in thousands) Derivative liabilities: Not subject to master netting arrangements: Interest rate lock commitments $ 3,418 $ — $ 3,418 $ 227 $ — $ 227 3,418 — 3,418 227 — 227 Subject to master netting arrangements: Forward purchase contracts 11,964 — 11,964 248 — 248 Forward sales contracts 1,719 — 1,719 2,830 — 2,830 Netting — (5,221 ) (5,221 ) — (1,999 ) (1,999 ) 13,683 (5,221 ) 8,462 3,078 (1,999 ) 1,079 17,101 (5,221 ) 11,880 3,305 (1,999 ) 1,306 Assets sold under agreements to repurchase: UPB 4,394,597 — 4,394,597 3,182,504 — 3,182,504 Unamortized debt issuance costs (97 ) — (97 ) (1,618 ) — (1,618 ) 4,394,500 — 4,394,500 3,180,886 — 3,180,886 $ 4,411,601 $ (5,221 ) $ 4,406,380 $ 3,184,191 $ (1,999 ) $ 3,182,192 Derivative Liabilities, Financial Liabilities and Collateral Pledged by Counterparty The following table summarizes by significant counterparty the amount of derivative liabilities and assets sold under agreements to repurchase after considering master netting arrangements and financial instruments or cash pledged that do not meet the accounting guidance qualifying for setoff accounting. All assets sold under agreements to repurchase represent sufficient collateral or exceed the liability amount recorded on the consolidated balance sheet. September 30, 2018 December 31, 2017 Net amount of liabilities presented in the Gross amounts not offset in the consolidated balance sheet Net amount of liabilities presented in the Gross amounts not offset in the consolidated balance sheet consolidated balance sheet Financial instruments Cash collateral pledged Net amount consolidated balance sheet Financial instruments Cash collateral pledged Net amount (in thousands) Interest rate lock commitments $ 3,418 $ — $ — $ 3,418 $ 227 $ — $ — $ 227 Bank of America, N.A. 1,424,559 (1,424,559 ) — — 839,057 (838,771 ) — 286 Deutsche Bank Securities LLC 701,294 (701,294 ) — — 374,526 (374,526 ) — — Credit Suisse Securities (USA) LLC 683,565 (683,339 ) — 226 845,567 (845,567 ) — — J.P. Morgan Securities LLC 448,773 (448,773 ) — — 373,186 (373,186 ) — — Mizuho Securities 276,791 (276,791 ) — — — — — — Daiwa Capital Markets 262,985 (262,940 ) — 45 153,833 (153,730 ) — 103 Morgan Stanley & Co. LLC 224,035 (223,627 ) — 408 164,530 (164,530 ) — — Citigroup Global Markets Inc. 118,762 (116,091 ) — 2,671 235,541 (235,319 ) — 222 RBC Capital Markets, L.P. 95,027 (95,027 ) — — 92,014 (91,805 ) — 209 BNP Paribas 91,062 (91,062 ) — — 45,411 (45,411 ) — — Wells Fargo Securities, LLC 71,094 (71,094 ) — — 50,360 (50,360 ) — — Federal National Mortgage Association 4,350 — — 4,350 — — — — Barclays Capital Inc. 270 — — 270 9,374 (9,299 ) — 75 Other 492 — — 492 184 — — 184 Unamortized debt issuance costs (97 ) 97 — — (1,618 ) 1,618 — — $ 4,406,380 $ (4,394,500 ) $ — $ 11,880 $ 3,182,192 $ (3,180,886 ) $ — $ 1,306 Following are the net gains (losses) recognized by the Company on derivative financial instruments and the consolidated statements of income line items where such gains and losses are included: Quarter ended September 30, Nine months ended September 30, Derivative activity Income statement line 2018 2017 2018 2017 (in thousands) Interest rate lock commitments Net gain on mortgage loans acquired for sale $ (7,700 ) $ 24,694 $ (26,431 ) $ 70,131 CRT agreements Net gain (loss) on investments $ 30,552 $ 14,960 $ 92,621 $ 68,863 Repurchase agreement derivatives Interest expense $ (37 ) $ — $ (118 ) $ — Hedged item: Interest rate lock commitments and mortgage loans acquired for sale Net gain on mortgage loans acquired for sale $ 15,584 $ (16,943 ) $ 56,818 $ (32,308 ) Mortgage servicing rights Net mortgage loan servicing fees $ (12,093 ) $ 4,576 $ (44,378 ) $ (1,731 ) Fixed-rate assets and LIBOR- indexed repurchase agreements Net gain (loss) on investments $ 691 $ (5,910 ) $ 1,029 $ (14,943 )

Real Estate Acquired in Settlem

Real Estate Acquired in Settlement of Loans	9 Months Ended
	Sep. 30, 2018
Banking And Thrift [Abstract]
Real Estate Acquired in Settlement of Loans	Note 12—Real Estate Acquired in Settlement of Loans Following is a summary of financial information relating to REO: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance at beginning of period $ 109,271 $ 207,034 $ 162,865 $ 274,069 Transfers: From mortgage loans at fair value and advances 7,508 22,951 26,229 76,981 To real estate held for investment (559 ) (2,555 ) (4,123 ) (14,300 ) From real estate held for investment 655 — 1,112 — Results of REO: Valuation adjustments, net (3,323 ) (6,423 ) (13,990 ) (21,749 ) Gain on sale, net 3,013 3,280 8,157 10,895 (310 ) (3,143 ) (5,833 ) (10,854 ) Sales (20,960 ) (39,253 ) (84,645 ) (140,862 ) Balance at end of period $ 95,605 $ 185,034 $ 95,605 $ 185,034 September 30, 2018 December 31, 2017 (in thousands) REO pledged to secure assets sold under agreements to repurchase $ 43,970 $ 76,037 REO held in a consolidated subsidiary whose stock is pledged to secure financings of such properties 25,429 48,495 $ 69,399 $ 124,532

Mortgage Servicing Rights

Mortgage Servicing Rights	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Mortgage Servicing Rights	Note 13—Mortgage Servicing Rights Carried at Fair Value: Following is a summary of MSRs carried at fair value: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance at beginning of period $ 1,010,507 $ 77,624 $ 91,459 $ 64,136 Transfer of mortgage servicing rights from mortgage servicing rights carried at lower of amortized cost or fair value pursuant to a change in accounting principle — — 773,035 — Balance after reclassification 1,010,507 77,624 864,494 64,136 Purchases — 10 — 79 Sales (100 ) — (100 ) — MSRs resulting from mortgage loan sales 96,383 8,655 228,337 28,467 Changes in fair value: Due to changes in valuation inputs used in valuation model (1) 33,004 (2,628 ) 101,699 (6,956 ) Other changes in fair value (2) (30,053 ) (1,349 ) (84,689 ) (3,414 ) 2,951 (3,977 ) 17,010 (10,370 ) Balance at end of period $ 1,109,741 $ 82,312 $ 1,109,741 $ 82,312 September 30, 2018 December 31, 2017 (in thousands) Fair value of mortgage servicing rights pledged to secure Assets sold under agreements to repurchase and (3) $ 1,090,406 $ 90,284 (1) Principally reflects changes in pricing spread (discount rate) and prepayment speed inputs, primarily due to changes in market interest rates. (2) Represents changes due to realization of expected cash flows. (3) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable Notes Payable Carried at Lower of Amortized Cost or Fair Value: Following is a summary of MSRs carried at lower of amortized cost or fair value: Quarter ended September 30, Nine months ended September 30, 2017 2018 2017 (in thousands) Amortized Cost: Balance at beginning of period $ 673,433 $ 772,870 $ 606,103 Transfer of mortgage servicing right to mortgage servicing rights carried at fair value pursuant to a change in accounting principle — (772,870 ) — Balance after reclassification 673,433 — 606,103 MSRs resulting from mortgage loan sales 74,183 — 178,894 Amortization (21,634 ) — (59,015 ) Balance at end of period 725,982 — 725,982 Valuation Allowance: Balance at beginning of period (16,257 ) (19,548 ) (13,672 ) Reduction resulting from change in accounting principle — 19,548 — Balance after reclassification (16,257 ) — (13,672 ) Additions to valuation allowance (1,702 ) — (4,287 ) Balance at end of period (17,959 ) — (17,959 ) MSRs, net $ 708,023 $ — $ 708,023 Fair value at beginning of period $ 682,437 $ 626,334 Fair value at end of period $ 728,828 December 31, 2017 (in thousands) MSRs carried at lower of cost or fair value pledged to secure: Assets sold under agreements to repurchase $ 584,762 Notes payable 156,846 $ 741,608 Servicing fees relating to MSRs are recorded in Net mortgage loan servicing fees Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Contractually-specified servicing fees $ 49,864 $ 42,237 $ 147,262 $ 119,223 Ancillary and other fees: Late charges 252 173 685 536 Other 2,859 1,870 5,988 4,110 $ 52,975 $ 44,280 $ 153,935 $ 123,869

Assets Sold Under Agreements to

Assets Sold Under Agreements to Repurchase	9 Months Ended
	Sep. 30, 2018
Brokers And Dealers [Abstract]
Assets Sold Under Agreements to Repurchase	Note 14—Assets Sold Under Agreements to Repurchase Following is a summary of financial information relating to assets sold under agreements to repurchase: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average interest rate (1) 3.19 % 2.72 % 3.12 % 2.57 % Average balance $ 4,072,301 $ 3,474,903 $ 3,573,805 $ 3,388,626 Total interest expense (2) $ 29,725 $ 26,157 $ 79,705 $ 72,280 Maximum daily amount outstanding $ 5,091,893 $ 3,973,869 $ 5,677,797 $ 4,083,326 (1) Excludes the effect of amortization of net debt issuance premiums of $3.1 million and $4.8 million for the quarter and nine months ended September 30, 2018, respectively, and net debt issuance costs of $1.9 million and $6.1 million for the quarter and nine months ended September 30, 2017, respectively. (2) The Company’s interest expense relating to assets sold under agreements to repurchase for the quarter and nine months ended September 30, 2018 includes recognition of incentives it received for financing certain of its mortgage loans acquired for sale satisfying certain consumer debt relief characteristics under a master repurchase agreement. During the quarter and nine months ended September 30, 2018, the Company recognized $5.0 million and $11.0 million, respectively, in such incentives as a reduction of interest expense. The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity. September 30, 2018 December 31, 2017 (dollars in thousands) Carrying value: Unpaid principal balance $ 4,394,597 $ 3,182,504 Unamortized debt issuance costs and premiums, net (97 ) (1,618 ) $ 4,394,500 $ 3,180,886 Weighted-average interest rate 3.23 % 2.77 % Available borrowing capacity (1): Committed $ 564,023 $ 749,650 Uncommitted 1,947,494 2,030,607 $ 2,511,517 $ 2,780,257 Margin deposits placed with counterparties included in Other $ 42,550 $ 28,154 Assets securing agreements to repurchase: Mortgage-backed securities $ 2,126,507 $ 989,461 Mortgage loans acquired for sale at fair value $ 1,898,155 $ 1,201,992 Mortgage loans at fair value $ 332,093 $ 760,853 CRT Agreements: Deposits securing CRT agreements $ 378,090 $ 400,778 Derivative assets $ 27,710 $ 26,058 Real estate acquired in settlement of loans $ 69,399 $ 124,532 Real estate held for investment $ 31,795 $ 31,128 MSRs (2) $ 1,090,406 $ 651,575 (1) The amount the Company is able to borrow under asset repurchase agreements is tied to the fair value of unencumbered assets eligible to secure those agreements and the Company’s ability to fund the agreements’ margin requirements relating to the assets financed. (2) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable Notes Payable Following is a summary of maturities of outstanding assets sold under agreements to repurchase by facility maturity date: Remaining maturity at September 30, 2018 Contractual balance (in thousands) Within 30 days $ 2,462,431 Over 30 to 90 days — Over 90 days to 180 days 10,328 Over 180 days to 1 year 1,815,302 Over one year to two years 106,536 $ 4,394,597 Weighted average maturity (in months) 3.9 The Company is subject to margin calls during the period the repurchase agreements are outstanding and therefore may be required to repay a portion of the borrowings before the respective repurchase agreements mature if the fair value (as determined by the applicable lender) of the assets securing those repurchase agreements decreases. The amount at risk (the fair value of the assets pledged plus the related margin deposit, less the amount advanced by the counterparty and interest payable) and maturity information relating to the Company’s assets sold under agreements to repurchase is summarized by pledged asset and counterparty below as of September 30, 2018: Mortgage loans, REO and MSRs sold under agreements to repurchase Counterparty Amount Weighted-average maturity Facility maturity (in thousands) Credit Suisse First Boston Mortgage Capital LLC $ 696,567 December 17, 2018 April 26, 2019 JPMorgan Chase & Co. $ 4,354 November 17, 2018 October 11, 2019 JPMorgan Chase & Co. $ 100,153 March 14, 2019 March 14, 2019 Citibank, N.A. $ 118,546 December 13, 2018 June 7, 2019 Bank of America, N.A. $ 16,589 October 18, 2018 July 1, 2019 Deutsche Bank $ 33,676 December 17, 2018 March 31, 2019 BNP Paribas Corporate & Institutional Banking $ 555 December 14, 2018 August 2, 2019 Morgan Stanley $ 10,781 December 13, 2018 August 23, 2019 Royal Bank of Canada $ 4,454 January 13, 2019 April 16, 2019 Securities sold under agreements to repurchase Counterparty Amount at risk Weighted average maturity (in thousands) JPMorgan Chase & Co. $ 20,251 October 26, 2018 Bank of America, N.A. $ 47,090 October 21, 2018 Daiwa Capital Markets America Inc. $ 16,385 October 19, 2018 Mizuho Securities $ 8,634 October 10, 2018 Wells Fargo, N.A. $ 4,034 October 16, 2018 CRT Agreements sold under agreements to repurchase Counterparty Amount at risk Weighted average maturity (in thousands) Credit Suisse First Boston Mortgage Capital LLC $ 50,793 October 10, 2018 Bank of America, N.A. $ 25,475 October 19, 2018 BNP Paribas Corporate & Institutional Banking $ 17,009 October 22, 2018

Mortgage Loan Participation Pur

Mortgage Loan Participation Purchase and Sale Agreements	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Mortgage Loan Participation Purchase and Sale Agreements	Note 15—Mortgage Loan Participation Purchase and Sale Agreements Certain borrowing facilities secured by mortgage loans acquired for sale are in the form of mortgage loan participation purchase and sale agreements. Participation certificates, each of which represents an undivided beneficial ownership interest in a pool of mortgage loans that have been pooled with Fannie Mae or Freddie Mac, are sold to a lender pending the securitization of such mortgage loans and the sale of the resulting security. The commitment between the Company and a nonaffiliate to sell such security is also assigned to the lender at the time a participation certificate is sold. The purchase price paid by the lender for each participation certificate is based on the trade price of the security, plus an amount of interest expected to accrue on the security to its anticipated delivery date, minus a present value adjustment, any related hedging costs and a holdback amount. The holdback amount is based on a percentage of the purchase price and is not required to be paid to the Company until the settlement of the security and its delivery to the lender. Mortgage loan participation purchase and sale agreements are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average interest rate (1) 3.39 % 2.48 % 3.21 % 2.28 % Average balance $ 78,806 $ 59,701 $ 51,687 $ 65,290 Total interest expense $ 739 $ 409 $ 1,396 $ 1,225 Maximum daily amount outstanding $ 258,983 $ 99,441 $ 258,983 $ 99,441 (1) Excludes the effect of amortization of debt issuance costs of $65,000 and $141,000 for the quarter and nine months ended September 30, 2018, respectively, and $31,000 and $94,000 for the quarter and nine months ended September 30, 2017, respectively. September 30, 2018 December 31, 2017 (dollars in Carrying value: Amount outstanding $ 31,675 $ 44,550 Unamortized debt issuance costs (97 ) (62 ) $ 31,578 $ 44,488 Weighted-average interest rate 3.61 % 2.82 % Mortgage loans acquired for sale pledged to secure mortgage loan participation purchase and sale agreements $ 32,392 $ 47,285

Exchangeable Senior Notes

Exchangeable Senior Notes	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Exchangeable Senior Notes	Note 16—Exchangeable Senior Notes PMC issued in a private offering $250 million aggregate principal amount of exchangeable senior notes (“Exchangeable Notes”) due May 1, 2020. The Exchangeable Notes bear interest at a rate of 5.375% per year, payable semiannually. The Exchangeable Notes are exchangeable into common shares of the Company at a rate of 33.8667 common shares per $1,000 principal amount of the Exchangeable Notes as of September 30, 2018, which is an increase over the initial exchange rate of 33.5149. The increase in the calculated exchange rate was the result of quarterly cash dividends exceeding the quarterly dividend threshold amount of $0.57 per share in prior reporting periods, as provided in the related indenture. Following is financial information relating to the Exchangeable Notes: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Average balance $ 250,000 $ 250,000 $ 250,000 $ 250,000 Total interest expense $ 3,652 $ 3,636 $ 10,945 $ 10,895 September 30, 2018 December 31, 2017 (in thousands) Carrying value: UPB $ 250,000 $ 250,000 Unamortized debt issuance costs (1,947 ) (2,814 ) $ 248,053 $ 247,186

Notes Payable

Notes Payable	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Notes Payable	Note 17—Notes Payable On April 25, 2018, the Company, through its indirect subsidiary, PMT ISSUER TRUST-FMSR (“FMSR Issuer Trust”), issued an aggregate principal amount of $450 million in secured term notes (the “2018-FT1 Notes”) to qualified institutional buyers under Rule 144A of the Securities Act of 1933, as amended. The 2018-FT1 Notes bear interest at a rate equal to one-month LIBOR plus 2.35% per annum, payable each month beginning in May 2018, on the 25 th th The 2018-FT1 Notes mature on April 25, 2023 or, if extended pursuant to the terms of the related term note indenture supplement, April 25, 2025 (unless earlier redeemed in accordance with their terms). The 2018-FT1 Notes rank pari passu with the Series 2017-VF1 Note dated December 20, 2017 (the “FMSR VFN”) pledged to Credit Suisse under an agreement to repurchase. The 2018-FT1 Notes and the FMSR VFN are secured by certain participation certificates relating to Fannie Mae MSRs and ESS relating to such MSRs. On February 1, 2018, the Company, through PMC and PMH, entered into a Loan and Security Agreement with Credit Suisse First Boston Mortgage Capital LLC (“Credit Suisse”), pursuant to which PMC and PMH may finance certain mortgage servicing rights (inclusive of any related excess servicing spread arising therefrom and that may be transferred from PMC to PMH from time to time) relating to mortgage loans pooled into Freddie Mac securities (collectively, the “Freddie MSRs”), in an aggregate loan amount not to exceed $175 million, all of which is committed. The note matures on February 1, 2020. On March 24, 2017, the Company, through PMC and PMH, entered into a second Amended and Restated Loan and Security Agreement with Citibank, N.A., pursuant to which PMC and PMH finance certain MSRs (inclusive of any related excess servicing spread and/or junior excess strips arising therefrom and that may be transferred from PMC to PMH from time to time) relating to mortgage loans pooled into Fannie Mae securities (collectively, the “Fannie MSRs”) in an aggregate loan amount not to exceed $400 million, all of which is committed. The note was redeemed and terminated in December 2017. On March 24, 2017, the Company, through PMC and PMH, entered into a Loan and Security Agreement with Barclays Bank PLC (“Barclays”), pursuant to which PMC and PMH may finance certain mortgage servicing rights (inclusive of any related excess servicing spread arising therefrom and that may be transferred from PMC to PMH from time to time) relating to mortgage loans pooled into Freddie Mac securities (collectively, the “Freddie MSRs”), in an aggregate loan amount not to exceed $170 million, all of which is committed. The note matured and was repaid on February 1, 2018. Following is a summary of financial information relating to the notes payable: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars Weighted-average interest rate (1) 4.53 % 6.30 % 4.58 % 5.57 % Average balance $ 445,149 $ 79,345 $ 251,052 $ 152,395 Total interest expense $ 5,351 $ 2,320 $ 9,032 $ 9,719 Maximum daily amount outstanding $ 445,318 $ 160,106 $ 445,318 $ 275,106 (1) Excludes the effect of amortization of debt issuance costs of $255,000 and $426,000 for the quarter and nine months ended September 30, 2018, respectively, and $1.0 million and $3.3 million for the quarter and nine months ended September 30, 2017, respectively. September 30, 2018 December 31, 2017 (dollars in thousands) Carrying value: Amount outstanding $ 450,000 $ — Unamortized debt issuance costs (4,682 ) — $ 445,318 $ — Weighted-average interest rate 4.44 % — MSRs pledged to secure notes payable (1) $ 1,090,406 $ 180,317 (1) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable

Asset-Backed Financing of a Var

Asset-Backed Financing of a Variable Interest Entity at Fair Value	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Asset-Backed Financing of a Variable Interest Entity at Fair Value	Note 18—Asset-Backed Financing of a Variable Interest Entity at Fair Value Following is a summary of financial information relating to the asset-backed financing of a VIE: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average fair value $ 285,284 $ 325,763 $ 292,770 $ 337,073 Total interest expense $ 2,740 $ 3,515 $ 7,836 $ 10,520 Weighted-average interest rate 3.52 % 3.34 % 3.51 % 3.41 % September 30, 2018 December 31, 2017 (dollars in thousands) Fair value $ 278,113 $ 307,419 UPB $ 287,086 $ 316,684 Weighted-average interest rate 3.51 % 3.51 % The asset-backed financing of a VIE is a non-recourse liability and secured solely by the assets of a consolidated VIE and not by any other assets of the Company. The assets of the VIE are the only source of funds for repayment of the certificates.

Liability for Losses Under Repr

Liability for Losses Under Representations and Warranties	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Liability for Losses Under Representations and Warranties	Note 19—Liability for Losses Under Representations and Warranties Following is a summary of the Company’s liability for losses under representations and warranties: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance, beginning of period $ 7,625 $ 10,697 $ 8,678 $ 15,350 Provision for losses: Pursuant to mortgage loan sales 636 1,075 1,724 2,355 Reduction in liability due to change in estimate (848 ) (1,642 ) (3,030 ) (7,523 ) (Losses incurred) recoveries, net — (83 ) 41 (135 ) Balance, end of period $ 7,413 $ 10,047 $ 7,413 $ 10,047 UPB of mortgage loans subject to representations and warranties at end of period $ 83,370,583 $ 67,196,537

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 20—Commitments and Contingencies Litigation From time to time, the Company may be involved in various proceedings, claims and legal actions arising in the ordinary course of business. As of September 30, 2018, the Company was not involved in any such proceedings, claims or legal actions that in the Manager’s view would reasonably be likely to have a material adverse effect on the Company. Commitments The following table summarizes the Company’s outstanding contractual commitments: September 30, 2018 (in thousands) Commitments to purchase mortgage loans acquired for sale $ 1,682,007 Commitments to fund Deposits securing CRT agreements $ 578,508 Firm commitment to purchase credit risk transfer security $ 294,698 (1) Certain deposits of cash collateral on CRT Agreements are made upon the first to occur of fulfillment of the aggregation obligation or the lapse of the aggregation period.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Shareholders' Equity	Note 21—Shareholders’ Equity Preferred Shares of Beneficial Interest Preferred shares of beneficial interest are summarized below: Series Description (1) Number of shares Liquidation preference Issuance discount Carrying value (in thousands) A 8.125% fixed-to-floating rate cumulative redeemable preferred, issued March 2017 4,600 $ 115,000 $ 3,828 $ 111,172 B 8.00% fixed-to-floating rate cumulative redeemable preferred, issued July 2017 7,800 195,000 6,465 188,535 12,400 $ 310,000 $ 10,293 $ 299,707 (1) Par value is $0.01 per share for both series. During March 2017, the Company issued 4.6 million of its 8.125% Series A Fixed-to-Floating Rate Cumulative Redeemable Preferred Shares of Beneficial Interest, $0.01 par value per share (the “Series A Preferred Shares”). From, and including, the date of original issuance to, but not including, March 15, 2024, the Company pays cumulative dividends on the Series A Preferred Shares at a fixed rate of 8.125% per annum based on the $25.00 per share liquidation preference. From, and including, March 15, 2024 and thereafter, the Company will pay cumulative dividends on the Series A Preferred Shares at a floating rate equal to three-month LIBOR as calculated on each applicable dividend determination date plus a spread of 5.831% per annum based on the $25.00 per share liquidation preference. The Company paid dividends of $1.52 per Series A Preferred Share during the nine months ended September 30, 2018. During July 2017, the Company issued 7.8 million of its 8.00% Series B Fixed-to-Floating Rate Cumulative Redeemable Preferred Shares of Beneficial Interest, $0.01 par value per share (the “Series B Preferred Shares” and, together with the Series A Preferred Shares, the “Preferred Shares”). From, and including, the date of original issuance to, but not including, June 15, 2024, the Company pays cumulative dividends on the Series B Preferred Shares at a fixed rate of 8.00% per annum based on the $25.00 per share liquidation preference. From, and including, June 15, 2024 and thereafter, the Company will pay cumulative dividends on the Series B Preferred Shares at a floating rate equal to three-month LIBOR as calculated on each applicable dividend determination date plus a spread of 5.99% per annum based on the $25.00 per share liquidation preference. The Company paid dividends of $1.50 per Series B Preferred Share for the nine months ended September 30, 2018. The Company pays quarterly cumulative dividends on its Preferred Shares on the 15 th The Series A and Series B Preferred Shares will not be redeemable before March 15, 2024 and June 15, 2024, respectively, except in connection with the Company’s qualification as a REIT for U.S. federal income tax purposes and upon the occurrence of a change of control. On or after the date the Preferred Shares become redeemable, or 120 days after the first date on which such change of control occurred, the Company may, at its option, redeem any or all of the Preferred Shares at $25.00 per share plus any accumulated and unpaid dividends thereon to, but not including, the redemption date. The Preferred Shares have no stated maturity, are not subject to any sinking fund or mandatory redemption and will remain outstanding indefinitely unless redeemed or repurchased by the Company or converted into common shares in connection with a change of control by the holders of the Preferred Shares. Common Share Repurchases During August 2015, the Company’s board of trustees authorized a common share repurchase program. Under the program, as amended, the Company may repurchase up to $300 million of its outstanding common shares. The following table summarizes the Company’s share repurchase activity: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Cumulative total (1) (in thousands) Common shares repurchased — 966 671 1,105 14,731 Cost of common shares repurchased $ — $ 16,417 $ 10,719 $ 18,724 $ 216,625 (1) Amounts represent the share repurchase program total from its inception in August 2015 through September 30, 2018. The repurchased common shares were canceled upon settlement of the repurchase transactions and returned to the authorized but unissued common share pool. Conditional Reimbursement of IPO Underwriting Costs As more fully described in Note 5— Transactions with Related Parties The Reimbursement Agreement also provides for the payment to the IPO underwriters of the amount that the Company agreed to pay to them at the time of the IPO if the Company satisfied certain performance measures over a specified period of time. As the Manager earns performance incentive fees under the management agreement, the IPO underwriters will be paid at a rate of $20 of payments for every $100 of performance incentive fees earned by PCM. The payment to the underwriters is subject to a maximum reimbursement in any particular 12-month period of $2.0 million and the maximum amount that may be paid under the agreement is $5.9 million. No payments were made during the quarter and nine months ended September 30, 2018. The Company paid reimbursements totaling $61,000 during the quarter and nine months ended September 30, 2017. During the quarter ended September 30, 2018, the Company incurred performance incentive fees of $683,000. Accordingly, the Company will reimburse the underwriters $137,000 during the quarter ending December 31, 2018. The Reimbursement Agreement expires on February 1, 2019.

Net Mortgage Loan Servicing Fee

Net Mortgage Loan Servicing Fees	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Net Mortgage Loan Servicing Fees	Note 22—Net Mortgage Loan Servicing Fees Net mortgage loan servicing fees are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Servicing fees (1) $ 49,864 $ 42,237 $ 147,262 $ 119,223 Ancillary and other fees 3,111 2,043 6,673 4,646 Effect of MSRs: Carried at fair value—change in fair value Realization of cashflows (30,053 ) (2,628 ) (84,689 ) (6,956 ) Other 33,127 (1,349 ) 101,822 (3,414 ) 3,074 (3,977 ) 17,133 (10,370 ) Loss on sale (123 ) — (123 ) — Carried at lower of amortized cost or fair value: Amortization — (21,634 ) — (59,015 ) Additions to impairment valuation allowance — (1,702 ) — (4,287 ) (Losses) gains on hedging derivatives (12,093 ) 4,576 (44,378 ) (1,731 ) (9,142 ) (22,737 ) (27,368 ) (75,403 ) 43,833 21,543 126,567 48,466 From PFSI—MSR recapture income 561 333 1,568 859 Net mortgage loan servicing fees $ 44,394 $ 21,876 $ 128,135 $ 49,325 Average servicing portfolio $ 81,350,980 $ 63,584,416 $ 77,522,709 $ 61,764,228 (1) Includes contractually specified servicing fees, net of Agency guarantee fees.

Net Gain on Mortgage Loans Acqu

Net Gain on Mortgage Loans Acquired for Sale	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Net Gain on Mortgage Loans Acquired for Sale	Note 23—Net Gain on Mortgage Loans Acquired for Sale Net gain on mortgage loans acquired for sale is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Cash loss: Mortgage loans $ (104,475 ) $ (51,485 ) $ (272,496 ) $ (135,666 ) Hedging activities 24,659 (13,468 ) 63,047 (16,931 ) (79,816 ) (64,953 ) (209,449 ) (152,597 ) Non cash gain: Recognition of fair value of firm commitment to purchase credit risk transfer security 12,311 — 16,737 — Receipt of MSRs in mortgage loan sale transactions 96,383 82,838 228,337 207,361 Provision for losses relating to representations and warranties provided in mortgage loan sales: Pursuant to mortgage loans sales (636 ) (1,075 ) (1,724 ) (2,355 ) Reduction in liability due to change in estimate 848 1,642 3,030 7,523 212 567 1,306 5,168 Change in fair value of financial instruments held at end of period: IRLCs (3,907 ) 880 (5,733 ) (2,502 ) Mortgage loans 6,013 (1,165 ) 8,389 2,891 Hedging derivatives (9,075 ) (3,475 ) (6,229 ) (15,377 ) (6,969 ) (3,760 ) (3,573 ) (14,988 ) Total from non-affiliates 22,121 14,692 33,358 44,944 From PFSI—cash gain 2,689 3,275 8,221 9,340 $ 24,810 $ 17,967 $ 41,579 $ 54,284

Net Gain (Loss) on Investments

Net Gain (Loss) on Investments	9 Months Ended
	Sep. 30, 2018
Investments Debt And Equity Securities [Abstract]
Net Gain (Loss) on Investments	Note 24—Net Gain (Loss) on Investments Net gain (loss) on investments is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Mortgage-backed securities at fair value $ (19,030 ) $ 5,001 $ (50,288 ) $ 9,168 Mortgage loans at fair value: Distressed (3,051 ) 3,277 (17,702 ) 7,523 Held in a VIE (3,630 ) 2,138 (11,992 ) 6,309 CRT Agreements 29,481 15,151 90,528 66,591 Asset-backed financing of a VIE at fair value 3,516 (2,158 ) 12,658 (5,581 ) Hedging derivatives 691 (5,910 ) 1,029 (14,943 ) 7,977 17,499 24,233 69,067 From PFSI—ESS 1,706 (3,665 ) 10,977 (10,920 ) $ 9,683 $ 13,834 $ 35,210 $ 58,147

Net Interest Income

Net Interest Income	9 Months Ended
	Sep. 30, 2018
Banking And Thrift Interest [Abstract]
Net Interest Income	Note 25—Net Interest Income Net interest income is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Interest income: From nonaffiliates: Short-term investments $ 385 $ 132 $ 656 $ 516 Mortgage-backed securities 15,903 7,447 37,127 21,954 Mortgage loans acquired for sale at fair value 22,591 16,202 51,874 40,699 Mortgage loans at fair value: Distressed 5,245 14,213 18,086 53,456 Held in a VIE 3,066 3,766 8,837 11,370 Deposits securing CRT Agreements 3,190 1,440 8,788 2,703 Placement fees relating to custodial funds 7,979 4,330 18,218 8,212 Other 225 49 478 142 58,584 47,579 144,064 139,052 From PFSI—ESS 3,740 3,998 11,584 13,011 62,324 51,577 155,648 152,063 Interest expense: To nonaffiliates: Assets sold under agreements to repurchase (1) 29,725 26,157 79,705 72,280 Mortgage loan participation purchase and sale agreements 739 409 1,396 1,225 Exchangeable Notes 3,652 3,636 10,945 10,895 Notes payable 5,351 2,320 9,032 9,719 Asset-backed financings of a VIE at fair value 2,740 3,515 7,836 10,520 Interest shortfall on repayments of mortgage loans serviced for Agency securitizations 1,897 1,638 5,294 4,068 Interest on mortgage loan impound deposits 693 486 1,596 1,229 44,797 38,161 115,804 109,936 To PFSI—Assets sold under agreement to repurchase 1,812 2,116 5,686 5,946 46,609 40,277 121,490 115,882 Net interest income $ 15,715 $ 11,300 $ 34,158 $ 36,181 (1) In 2017, the Company entered into a master repurchase agreement that provides the Company with incentives to finance mortgage loans approved for satisfying certain consumer relief characteristics as provided in the agreement. During the quarter and nine months ended September 30, 2018, the Company included $5.0 million and $11.0 million, respectively, of such incentives as a reduction of Interest expense

Share-Based Compensation Plans

Share-Based Compensation Plans	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation Plans	Note 26—Share-Based Compensation Plans As of September 30, 2018 and December 31, 2017, the Company had one share-based compensation plan. The following table summarizes the Company’s share-based compensation activity: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Grants: Restricted share units — 2 129 136 Performance share units — — 116 126 Total share units granted — 2 245 262 Grant date fair value: Restricted share units granted $ — $ 36 $ 2,281 $ 2,317 Performance share units granted — — 1,542 1,675 Total fair value of share units granted $ — $ 36 $ 3,823 $ 3,992 Vestings: Restricted share units 1 — 261 284 Performance share units — — 28 — Total share units vested 1 — 289 284 Forfeitures: Restricted share units 2 — 2 13 Performance share units — — — — Total share units forfeited 2 — 2 13 Compensation expense relating to share-based grants $ 1,566 $ 737 $ 4,322 $ 3,864

Other Expenses

Other Expenses	9 Months Ended
	Sep. 30, 2018
Other Income And Expenses [Abstract]
Other Expenses	Note 27—Other Expenses Other expenses are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Common overhead allocation from PFSI $ 1,210 $ 1,193 $ 3,387 $ 4,220 Technology 291 374 1,014 1,088 Insurance 274 300 915 968 Other 1,119 1,434 2,442 4,428 $ 2,894 $ 3,301 $ 7,758 $ 10,704

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 28—Income Taxes The Company’s effective tax rate was 9.9% and 15.6% for the quarter and nine months ended September 30, 2018. The Company’s taxable REIT subsidiary (“TRS”) recognized a tax expense of $4.8 million on income of $17.7 million and a tax expense of $19.9 million on income of $73.2 million while the Company’s reported consolidated pretax income was $51.7 million and $131.8 million for the quarter and nine months ended September 30, 2018, respectively. For the same periods in 2017, the Company’s TRS recognized tax expense of $4.8 million on income of $12.0 million and tax benefit of $900,000 on a loss of $4.5 million, respectively, while the Company’s reported consolidated pretax income was $24.2 million and $78.6 million, respectively. The relative values between the tax benefit or expense at the TRS and the Company’s consolidated pretax income drive the fluctuation in the effective tax rate. The primary difference between the Company’s effective tax rate and the statutory tax rate is due to nontaxable REIT income resulting from the dividends paid deduction. In general, cash dividends declared by the Company will be considered ordinary income to the shareholders for income tax purposes. Some portion of the dividends may be characterized as capital gain distributions or a return of capital. For tax years beginning after December 31, 2017, the 2017 Tax Cuts and Jobs Act (the “Tax Act”) (subject to certain limitations) provides a 20% deduction from taxable income for ordinary REIT dividends.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Note 29—Earnings Per Share The Company grants restricted share units which entitle the recipients to receive dividend equivalents during the vesting period on a basis equivalent to the dividends paid to holders of common shares. Unvested share-based compensation awards containing non-forfeitable rights to receive dividends or dividend equivalents (collectively, “dividends”) are classified as “participating securities” and are included in the basic earnings per share calculation using the two-class method. Under the two-class method, all earnings (distributed and undistributed) are allocated to common shares and participating securities, based on their respective rights to receive dividends. Basic earnings per share is determined by dividing net income available to common shareholders, reduced by income attributable to the participating securities, by the weighted-average common shares outstanding during the period. Diluted earnings per share is determined by dividing net income attributable to diluted shareholders, which adds back to net income the interest expense, net of applicable income taxes, on the Company’s Exchangeable Notes, by the weighted-average common shares outstanding, assuming all dilutive securities were issued. The following table summarizes the basic and diluted earnings per share calculations: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands except per share amounts) Net income $ 46,562 $ 19,395 $ 111,173 $ 76,911 Dividends on preferred shares (6,235 ) (6,125 ) (18,703 ) (9,032 ) Effect of participating securities—share-based compensation awards (236 ) (231 ) (541 ) (760 ) Net income attributable to common shareholders $ 40,091 $ 13,039 $ 91,929 $ 67,119 Net income attributable to common shareholders $ 40,091 $ 13,039 $ 91,929 $ 67,119 Interest on Exchangeable Notes, net of income taxes 2,661 — 7,973 6,564 Diluted net income attributable to common shareholders $ 42,752 $ 13,039 $ 99,902 $ 73,683 Weighted-average basic shares outstanding 60,950 66,636 60,880 66,702 Dilutive securities: Shares issuable pursuant to exchange of the Exchangeable Notes 8,467 — 8,467 8,467 Diluted weighted-average number of shares outstanding 69,417 66,636 69,347 75,169 Basic earnings per share $ 0.66 $ 0.20 $ 1.51 $ 1.01 Diluted earnings per share $ 0.62 $ 0.20 $ 1.44 $ 0.98 Calculation of diluted earnings per share requires certain potentially dilutive shares to be excluded when the inclusion of such shares in the diluted earnings per share calculation would be antidilutive. The following table summarizes the potentially dilutive shares excluded from the diluted earnings per share calculation, as inclusion of such shares would have been antidilutive: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Shares issuable under share-based compensation plan 361 643 403 699 Shares issuable pursuant to exchange of the Exchangeable Notes — 8,467 — —

Segments

Segments	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segments	Note 30—Segments The Company operates in four segments: correspondent production, credit sensitive strategies, interest rate sensitive strategies and corporate: • The correspondent production segment represents the Company’s operations aimed at serving as an intermediary between mortgage lenders and the capital markets by purchasing, pooling and reselling newly originated prime credit quality mortgage loans either directly or in the form of MBS, using the services of the Manager and PLS. • Most of the mortgage loans the Company has acquired in its correspondent production activities have been eligible for sale to GSEs such as Fannie Mae and Freddie Mac or through government agencies such as Ginnie Mae. • The credit sensitive strategies segment represents the Company’s investments in CRT Agreements, firm commitments to purchase CRT securities, distressed mortgage loans, REO, real estate held for investment, non-Agency subordinated bonds and small balance commercial real estate mortgage loans. • The interest rate sensitive strategies segment represents the Company’s investments in MSRs, ESS, Agency and senior non-Agency MBS and the related interest rate hedging activities. • The corporate segment includes certain interest income, management fee and corporate expense amounts. Financial highlights by operating segment are summarized below: Quarter ended September 30, 2018 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 5 $ 44,389 $ — $ 44,394 Net gain on mortgage loans acquired for sale 12,496 12,314 — — 24,810 Net gain (loss) on investments — 26,293 (16,610 ) — 9,683 Net interest income (expense): Interest income 22,465 8,675 30,573 611 62,324 Interest expense (12,708 ) (8,792 ) (25,109 ) — (46,609 ) 9,757 (117 ) 5,464 611 15,715 Other income 12,442 1,457 — — 13,899 34,695 39,952 33,243 611 108,501 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 26,256 1,271 8,800 — 36,327 Management fees — — — 6,482 6,482 Other 2,485 5,619 344 5,582 14,030 28,741 6,890 9,144 12,064 56,839 Pre-tax income (loss) $ 5,954 $ 33,062 $ 24,099 $ (11,453 ) $ 51,662 Total assets at end of quarter $ 1,976,188 $ 1,348,750 $ 3,822,572 $ 120,068 $ 7,267,578 Quarter ended September 30, 2017 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 47 $ 21,829 $ — $ 21,876 Net gain on mortgage loans acquired for sale 17,963 4 — — 17,967 Net gain (loss) on investments — 18,562 (4,728 ) — 13,834 Net interest income: Interest income 16,018 15,951 19,426 182 51,577 Interest expense (11,351 ) (13,096 ) (15,830 ) — (40,277 ) 4,667 2,855 3,596 182 11,300 Other income (loss) 11,762 (935 ) — — 10,827 34,392 20,533 20,697 182 75,804 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 23,508 4,273 7,128 — 34,909 Management fees — — — 6,038 6,038 Other 2,574 3,194 265 4,658 10,691 26,082 7,467 7,393 10,696 51,638 Pre-tax income (loss) $ 8,310 $ 13,066 $ 13,304 $ (10,514 ) $ 24,166 Total assets at end of quarter $ 1,304,647 $ 1,959,792 $ 2,414,477 $ 106,127 $ 5,785,043 Nine months ended September 30, 2018 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 29 $ 128,106 $ — $ 128,135 Net gain on mortgage loans acquired for sale 24,810 16,769 — — 41,579 Net gain (loss) on investments — 72,744 (37,534 ) — 35,210 Net interest income (expense): Interest income 51,456 27,634 75,423 1,135 155,648 Interest expense (30,039 ) (28,899 ) (62,552 ) — (121,490 ) 21,417 (1,265 ) 12,871 1,135 34,158 Other income (loss) 28,410 (351 ) — 24 28,083 74,637 87,926 103,443 1,159 267,165 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 52,759 5,529 24,992 — 83,280 Management fees — — — 17,906 17,906 Other 4,778 13,077 166 16,172 34,193 57,537 18,606 25,158 34,078 135,379 Pre-tax income (loss) $ 17,100 $ 69,320 $ 78,285 $ (32,919 ) $ 131,786 Total assets at end of period $ 1,976,188 $ 1,348,750 $ 3,822,572 $ 120,068 $ 7,267,578 Nine months ended September 30, 2017 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 91 $ 49,234 $ — $ 49,325 Net gain on mortgage loans acquired for sale 54,117 167 — — 54,284 Net gain (loss) on investments — 74,695 (16,548 ) — 58,147 Net interest income: Interest income 40,194 57,011 54,200 658 152,063 Interest expense (28,214 ) (41,178 ) (46,490 ) — (115,882 ) 11,980 15,833 7,710 658 36,181 Other income (loss) 30,576 (4,281 ) — 5 26,300 96,673 86,505 40,396 663 224,237 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 61,191 12,143 19,837 — 93,171 Management fees — — — 16,684 16,684 Other 6,614 11,419 1,094 16,656 35,783 67,805 23,562 20,931 33,340 145,638 Pre-tax income (loss) $ 28,868 $ 62,943 $ 19,465 $ (32,677 ) $ 78,599 Total assets at end of period $ 1,304,647 $ 1,959,792 $ 2,414,477 $ 106,127 $ 5,785,043

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Note 31—Supplemental Cash Flow Information Nine months ended September 30, 2018 2017 (in thousands) Income tax payments, net of refunds $ 900 $ (294 ) Interest payments $ 124,332 $ 115,108 Cumulative effect on accumulated deficit of conversion to fair value accounting $ 14,361 $ — Non-cash investing activities: Transfer of mortgage loans and advances to real estate acquired in settlement of loans $ 26,229 $ 76,981 Transfer of real estate acquired in settlement of mortgage loans to real estate held for investment $ 4,123 $ 14,300 Transfer of real estate acquired in settlement of mortgage loans from real estate held for investment $ 1,112 $ — Receipt of mortgage servicing rights as proceeds from sales of mortgage loans $ 228,337 $ 207,361 Receipt of excess servicing spread pursuant to recapture agreement with PennyMac Financial Services, Inc. $ 1,983 $ 4,160 Capitalization of servicing advances pursuant to mortgage loan modifications $ 4,734 $ 17,759 Non-cash financing activities: Recognition of financing premium arising from repurchase agreement derivatives $ 11,411 $ — Dividends declared, not paid $ 28,817 $ 31,655

Regulatory Capital and Liquidit

Regulatory Capital and Liquidity Requirements	9 Months Ended
	Sep. 30, 2018
Mortgage Banking [Abstract]
Regulatory Capital and Liquidity Requirements	Note 32—Regulatory Capital and Liquidity Requirements PMC is a seller/servicer for Fannie Mae and Freddie Mac. The Company is required to comply with the following minimum capital and liquidity eligibility requirements to remain in good standing with each Agency: • A minimum net worth of $2.5 million plus 25 basis points of UPB for all mortgage loans serviced; • A tangible net worth/total assets ratio greater than or equal to 6%; and • Liquidity equal to or exceeding 3.5 basis points multiplied by the aggregate UPB of all mortgages secured by 1-4 unit residential properties serviced for Freddie Mac and Fannie Mae (“Agency Mortgage Servicing”) plus 200 basis points multiplied by the sum of nonperforming (90 or more days delinquent) Agency Mortgage Servicing that exceeds 6% of Agency Mortgage Servicing. Such Agencies’ capital and liquidity amounts and requirements, the calculations of which are defined by each entity, are summarized below: Net Worth (1) Tangible Net Worth / Total Assets Ratio (1) Liquidity (1) Fannie Mae and Freddie Mac Actual Required Actual Required Actual Required (in thousands) (in thousands) September 30, 2018 $ 555,214 $ 213,379 11 % 6 % $ 100,478 $ 28,983 December 31, 2017 $ 487,535 $ 182,818 12 % 6 % $ 73,252 $ 25,245 (1) Calculated in accordance with the Agencies’ requirements. Noncompliance with the Agencies’ capital and liquidity requirements can result in the Agencies taking various remedial actions up to and including removing the Company’s ability to sell loans to and service loans on behalf of the Agencies.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 33—Subsequent Events Management has evaluated all events and transactions through the date the Company issued these consolidated financial statements. During this period: • During October of 2018, the Company settled its obligation to fund Deposits securing credit risk transfer agreements Deposits securing credit risk transfer agreements • During October 2018, the Company entered into four agreements to sell approximately $300 million in UPB of performing and nonperforming loans from the distressed portfolio. These transactions are subject to continuing due diligence and customary closing conditions and there can be no assurance regarding the size of these transactions or that these transactions will be completed at all. • All agreements to repurchase assets that matured between September 31, 2018 and the date of this Report were extended or renewed.

Organization and Basis of Prese

Organization and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Segment Reporting	The Company operates in four segments: correspondent production, credit sensitive strategies, interest rate sensitive strategies and corporate: • The correspondent production segment represents the Company’s operations aimed at serving as an intermediary between mortgage lenders and the capital markets by purchasing, pooling and reselling newly originated prime credit quality mortgage loans either directly or in the form of mortgage-backed securities (“MBS”), using the services of PNMAC Capital Management, LLC (“PCM” or the “Manager”) and PennyMac Loan Services, LLC (“PLS”), both indirect controlled subsidiaries of PennyMac Financial Services, Inc. (“PFSI”). • Most of the mortgage loans the Company has acquired in its correspondent production activities have been eligible for sale to government-sponsored entities (“GSEs”) such as the Federal National Mortgage Association (“Fannie Mae”) and the Federal Home Loan Mortgage Corporation (“Freddie Mac”) or through government agencies such as the Government National Mortgage Association (“Ginnie Mae”). Fannie Mae, Freddie Mac and Ginnie Mae are each referred to as an “Agency” and, collectively, as the “Agencies.” • The credit sensitive strategies segment represents the Company’s investments in credit risk transfer agreements (“CRT Agreements”), distressed mortgage loans, real estate acquired in settlement of mortgage loans (“REO”), real estate held for investment, non-Agency subordinated bonds and small balance commercial real estate mortgage loans. • The interest rate sensitive strategies segment represents the Company’s investments in mortgage servicing rights (“MSRs”), excess servicing spread purchased from PFSI (“ESS”), Agency and senior non-Agency MBS and the related interest rate hedging activities. • The corporate segment includes certain interest income, management fee and corporate expense amounts.
Basis of Presentation	The accompanying consolidated financial statements have been prepared in compliance with accounting principles generally accepted in the United States (“GAAP”) as codified in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification The accompanying unaudited consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, and cash flows for the interim periods, but are not necessarily indicative of the results of operations that may be anticipated for the full year. Intercompany accounts and transactions have been eliminated. Preparation of financial statements in compliance with GAAP requires the Manager to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the reporting period. Actual results will likely differ from those estimates.
Accounting Changes	Accounting Changes Mortgage Servicing Rights Effective January 1, 2018, the Company has elected to change the accounting for the classes of MSRs it accounted for using the amortization method through December 31, 2017, to the fair value method as allowed in the Transfers and Servicing
Revenue Recognition	Revenue Recognition As disclosed in Note 33 – Recently Issued Accounting Pronouncements Receivables, Investments and Debt and Equity Securities, Transfers and Servicing, Financial Instruments Derivatives and Hedging .
Cash Flows	Cash Flows During the nine months ended September 30, 2018, the Company adopted FASB Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230) – Restricted Cash
Recently Issued Accounting Pronouncement	Recently Issued Accounting Pronouncement On June 20, 2018, the FASB issued ASU 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ASU 2018-07 expands the scope of the Compensation—Stock Compensation The Company issues share-based compensation to certain employees of the Manager. Presently, the Company accounts for share-based payments to employees of the Manager under the guidance of Equity – Equity-Based Payments to Non-Employees The amendments in this ASU are effective for the Company for the fiscal year ending December 31, 2019, including interim periods within that fiscal year. Upon adoption, the Manager does not expect to record a cumulative effect adjustment to its accumulated deficit.
Fair Value Measurement	The Company’s consolidated financial statements include assets and liabilities that are measured based on their fair values. Measurement at fair value may be on a recurring or nonrecurring basis depending on the accounting principles applicable to the specific asset or liability and whether the Manager has elected to carry the item at its fair value as discussed in the following paragraphs. The Company groups its assets and liabilities at fair value in three levels, based on the markets in which the assets and liabilities are traded and the observability of the inputs used to determine fair value. These levels are: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Prices determined or determinable using other significant observable inputs. Observable inputs are inputs that other market participants would use in pricing the asset or liability and are developed based on market data obtained from sources independent of the Company. These may include quoted prices for similar assets or liabilities, interest rates, prepayment speeds, credit risk and other inputs. • Level 3—Prices determined using significant unobservable inputs. In situations where significant observable inputs are unavailable, unobservable inputs may be used. Unobservable inputs reflect the Company’s own judgments about the factors that market participants use in pricing assets and liabilities, and are based on the best information available in the circumstances. • As a result of the difficulty in observing certain significant valuation inputs affecting “Level 3” fair value assets and liabilities, the Manager is required to make judgments regarding these items’ fair values. Different persons in possession of the same facts may reasonably arrive at different conclusions as to the inputs to be applied in valuing these assets and liabilities and to their fair values. Such differences may result in significantly different fair value measurements. Likewise, due to the general illiquidity of some of these assets and liabilities, subsequent transactions may be at values significantly different from those reported. Fair Value Accounting Elections The Manager identified all of the Company’s non-cash financial assets, firm commitment to purchase credit risk transfer securities and MSRs to be accounted for at fair value. The Manager has elected to account for these assets at fair value so such changes in fair value will be reflected in income as they occur and more timely reflect the results of the Company’s performance. Before January 1, 2018, originated MSRs backed by mortgage loans with initial interest rates of less than or equal to 4.5% were accounted for using the amortization method. Beginning January 1, 2018, the Company elected to account for all MSRs at fair value prospectively. The Manager determined that this change makes the accounting treatment for MSRs consistent with lender valuation under financing arrangements and simplifies hedging activities. The Manager has also identified the Company’s asset-backed financing of a VIE and interest only security payable at fair value to be accounted for at fair value to reflect the generally offsetting changes in fair value of these borrowings to changes in fair value of the assets at fair value collateralizing these financings. For other borrowings, the Manager has determined that historical cost accounting is more appropriate because under this method debt issuance costs are amortized over the term of the debt facility, thereby matching the debt issuance cost to the periods benefiting from the availability of the debt.
Earnings Per Share	The Company grants restricted share units which entitle the recipients to receive dividend equivalents during the vesting period on a basis equivalent to the dividends paid to holders of common shares. Unvested share-based compensation awards containing non-forfeitable rights to receive dividends or dividend equivalents (collectively, “dividends”) are classified as “participating securities” and are included in the basic earnings per share calculation using the two-class method. Under the two-class method, all earnings (distributed and undistributed) are allocated to common shares and participating securities, based on their respective rights to receive dividends. Basic earnings per share is determined by dividing net income available to common shareholders, reduced by income attributable to the participating securities, by the weighted-average common shares outstanding during the period. Diluted earnings per share is determined by dividing net income attributable to diluted shareholders, which adds back to net income the interest expense, net of applicable income taxes, on the Company’s Exchangeable Notes, by the weighted-average common shares outstanding, assuming all dilutive securities were issued.

Concentration of Risks (Tables)

Concentration of Risks (Tables)	9 Months Ended
	Sep. 30, 2018
Risks And Uncertainties [Abstract]
Summary of Holdings of Assets Purchased	Most of the distressed mortgage loans and REO has been acquired by the Company in prior years from or through one or more subsidiaries of JPMorgan Chase & Co., Citigroup Inc., and Bank of America Corporation, as presented in the following summary: September 30, 2018 December 31, 2017 (in thousands) JPMorgan Chase & Co. Mortgage loans at fair value $ 135,486 $ 315,437 REO 42,003 66,294 177,489 381,731 Citigroup Inc. Mortgage loans at fair value 133,547 280,488 REO 13,223 26,702 146,770 307,190 Bank of America Corporation Mortgage loans at fair value 60,884 143,969 REO 15,786 27,970 76,670 171,939 $ 400,929 $ 860,860 Total carrying value of distressed mortgage loans at fair value and REO $ 436,599 $ 931,298

Transactions with Related Par_2

Transactions with Related Parties (Tables)	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Summary of Correspondent Production Activity	Following is a summary of correspondent production activity between the Company and PLS: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Mortgage loans fulfillment fees earned by PLS $ 26,256 $ 23,507 $ 52,759 $ 61,184 Unpaid principal balance ("UPB") of mortgage loans fulfilled by PLS $ 7,517,883 $ 6,530,036 $ 17,139,884 $ 17,079,969 Sourcing fees received from PLS included in Net gain on mortgage loans acquired for sale $ 2,689 $ 3,275 $ 8,221 $ 9,340 UPB of mortgage loans sold to PLS $ 8,916,654 $ 10,915,194 $ 27,404,022 $ 31,131,154 Early purchase program fees paid to PLS included in Mortgage loan servicing fees $ — $ 1 $ — $ 7 Purchases of mortgage loans acquired for sale from PLS $ 908,525 $ 332,886 $ 2,336,162 $ 373,108 Tax service fee paid to PLS included in Other $ 2,119 $ 2,108 $ 4,869 $ 5,377 September 30, 2018 December 31, 2017 (in thousands) Mortgage loans included in Mortgage loans acquired for sale at fair value pending sale to PLS $ 217,334 $ 279,571
Summary of Mortgage Loan Servicing Fees Earned and Mortgage Servicing Rights Recaptured Income Earned	Following is a summary of mortgage loan servicing fees earned by PLS and MSR recapture income earned from PLS: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Mortgage loans servicing fees: Mortgage loans acquired for sale at fair value: Base $ 98 $ 88 $ 250 $ 235 Activity-based 218 188 489 507 316 276 739 742 Mortgage loans at fair value: Distressed mortgage loans: Base 614 1,571 2,328 5,284 Activity-based 657 2,702 3,200 6,859 1,271 4,273 5,528 12,143 Mortgage loans held in VIE - Base 35 54 103 96 MSRs: Base 8,291 6,648 23,772 18,631 Activity-based 158 151 379 375 8,449 6,799 24,151 19,006 $ 10,071 $ 11,402 $ 30,521 $ 31,987 Average investment in: Mortgage loans acquired for sale at fair value $ 1,833,232 $ 1,460,054 $ 1,460,547 $ 1,271,158 Mortgage loans at fair value: Distressed mortgage loans $ 417,487 $ 1,104,738 $ 537,300 $ 1,210,328 Mortgage loans held in a VIE $ 299,415 $ 339,464 $ 306,856 $ 350,607 Average MSR portfolio $ 81,350,980 $ 63,584,416 $ 77,522,709 $ 61,764,228 MSR recapture income recognized included in Net mortgage loan servicing fees ‒ Financial Services, Inc. $ 561 $ 333 $ 1,568 $ 859
Summary of Base Management and Performance Incentive Fees Payable	Following is a summary of the base management and performance incentive fees payable to PCM recorded by the Company: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Base management $ 5,799 $ 6,038 $ 17,223 $ 16,380 Performance incentive 683 — 683 304 $ 6,482 $ 6,038 $ 17,906 $ 16,684
Summary of Expenses	Following is a summary of the Company’s reimbursements to PCM and its affiliates for expenses: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Reimbursement of: Common overhead incurred by PCM and its affiliates $ 1,210 $ 1,193 $ 3,387 $ 4,220 Compensation 120 — 360 — Expenses incurred on the Company’s behalf, net 527 196 586 849 $ 1,857 $ 1,389 $ 4,333 $ 5,069 Payments and settlements during the period (1) $ 21,650 $ 22,786 $ 45,265 $ 63,249 (1) Payments and settlements include payments and netting settlements made pursuant to master netting agreements between the Company and PFSI for the operating, investment and financing activities itemized in this Note.
Summary of Investing Activity	Following is a summary of investing activities between the Company and PFSI: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) ESS: Received pursuant to a recapture agreement $ 499 $ 1,207 $ 1,983 $ 4,160 Repayments $ 11,543 $ 13,410 $ 35,852 $ 42,320 Interest income $ 3,740 $ 3,998 $ 11,584 $ 13,011 Net gain (loss) included in Net gain (loss) on investments: Valuation changes $ 1,109 $ (4,828 ) $ 9,026 $ (14,757 ) Recapture income 597 1,163 1,951 3,837 $ 1,706 $ (3,665 ) $ 10,977 $ (10,920 ) September 30, 2018 December 31, 2017 (in thousands) Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value $ 223,275 $ 236,534
Summary Of Financing Transactions	Following is a summary of financing activities between the Company and PFSI: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Interest expense $ 1,812 $ 2,116 $ 5,686 $ 5,946 Conditional Reimbursements paid to PCM $ — $ 30 $ — $ 30 September 30, 2018 December 31, 2017 (in thousands) Assets sold to PFSI under agreement to repurchase $ 133,128 $ 144,128 Conditional Reimbursement payable to PFSI included in Accounts payable and accrued liabilities $ 870 $ 870
Summary of Amounts Receivable From and Payable to PFSI	Amounts receivable from and payable to PFSI are summarized below: September 30, 2018 December 31, 2017 (in thousands) Due from PFSI: MSR recapture receivable $ 250 $ 282 Other 2,101 3,872 $ 2,351 $ 4,154 Due to PFSI: Fulfillment fees $ 12,078 $ 346 Management fees 6,482 5,901 Mortgage loan servicing fees 3,765 6,583 Allocated expenses and expenses paid by PFSI on PMT’s behalf 2,295 11,542 Correspondent production fees 1,864 1,735 Conditional Reimbursement 870 870 Interest on Assets sold to PFSI under agreement to repurchase 113 142 $ 27,467 $ 27,119

Loan Sales and Variable Inter_2

Loan Sales and Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Cash Flows between Company and Transferees in Transfers Accounted for Sales	The following table summarizes cash flows between the Company and transferees in transfers of mortgage loans that are accounted for as sales where the Company maintains continuing involvement with the mortgage loans: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Cash flows: Proceeds from sales $ 8,435,791 $ 7,035,994 $ 18,992,722 $ 17,683,444 Mortgage loan servicing fees received (1) $ 49,864 $ 42,237 $ 147,262 $ 119,223 (1) Net of guarantee fees
Summary of Collection Status Information for Mortgage Loans Accounted for Sales	The following table summarizes collection status information for mortgage loans that are accounted for as sales where the Company maintains continuing involvement for the dates presented: September 30, 2018 December 31, 2017 (in thousands) UPB of mortgage loans outstanding $ 83,913,215 $ 71,639,351 UPB of delinquent mortgage loans: 30-89 days delinquent $ 601,114 $ 532,673 90 or more days delinquent: Not in foreclosure $ 140,122 $ 280,786 In foreclosure $ 36,069 $ 25,258 UPB of mortgage loans in bankruptcy $ 66,377 $ 52,202 Custodial funds managed by the Company (1) $ 1,203,229 $ 879,321 (1) Custodial funds include borrower and investor custodial cash accounts relating to mortgage loans serviced under mortgage servicing agreements and are not included on the Company’s consolidated balance sheets. The Company earns placement fees on certain of the custodial funds it manages on behalf of the mortgage loans’ investors, which are included in Interest income
Summary of Credit Risk Transfer Agreements	Following is a summary of the CRT Agreements: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) UPB of mortgage loans sold under CRT Agreements $ — $ 4,126,946 $ 5,546,977 $ 9,722,067 Deposits securing CRT Agreements $ 18,558 $ 44,998 $ 96,446 $ 102,146 (Decrease) increase in commitments to fund Deposits securing CRT Agreements resulting from sale of mortgage loans under CRT Agreements $ (18,558 ) $ 108,051 $ 96,037 $ 264,165 Interest earned on Deposits securing Agreements $ 3,190 $ 1,440 $ 8,788 $ 2,703 Gains recognized on CRT Agreements included in Net gain (loss) on investments Realized $ 23,367 $ 10,798 $ 64,907 $ 27,595 Resulting from valuation changes 7,185 4,162 27,714 41,268 30,552 14,960 92,621 68,863 Change in fair value of Interest-only security payable at fair value (3,083 ) 191 (4,105 ) (2,272 ) $ 27,469 $ 15,151 $ 88,516 $ 66,591 Payments made to settle losses $ 443 $ 539 $ 1,452 $ 950 September 30, 2018 December 31, 2017 (in thousands) UPB of mortgage loans subject to credit guarantee obligations $ 30,648,306 $ 26,845,392 Collection status (in UPB): Current $ 30,342,833 $ 26,540,953 30—89 days delinquent $ 226,447 $ 179,144 90—180 days delinquent $ 32,852 $ 101,114 180 or more days delinquent $ 15,520 $ 5,146 Foreclosure $ 9,339 $ 5,463 Bankruptcy $ 21,315 $ 13,572 Carrying value of CRT Agreements: Derivative assets $ 126,354 $ 98,640 Deposits securing CRT agreements $ 662,624 $ 588,867 Interest-only security payable at fair value $ 8,821 $ 7,070 CRT Agreement assets pledged to secure Assets sold under agreements to repurchase : Deposits securing CRT Agreements $ 378,090 $ 400,778 Derivative assets $ 27,710 $ 26,058 Commitments to fund Deposits securing credit risk transfer agreements $ 578,508 $ 482,471
Summary of Activity Under Purchase Commitments	Following is a summary of activity under these purchase commitments during the quarter and nine months ended September 30, 2018: Periods ended September 30, 2018 Quarter Nine months (in thousands) UPB of mortgage loans sold $ 6,773,336 $ 8,308,708 Fair value of firm commitment recognized in Gain on sale of mortgage loans $ 12,311 $ 16,737 Gains recognized on CRT Agreements included in Net gain (loss) on investments $ 2,012 $ 2,012 Increase in face amount of firm commitment to purchase securities backed by mortgage loans sold $ 236,875 $ 294,698 September 30, 2018 (in thousands) Firm commitment to purchase CRT securities $ 294,698 Fair value of firm commitment $ 18,749 UPB of mortgage loans sold subject to firm commitment to purchase securities related to such loans $ 8,097,660 Collection status (in UPB): Current $ 8,073,018 30—89 days delinquent $ 24,439 90—180 days delinquent $ 203 180 or more days delinquent $ — Foreclosure $ — Bankruptcy $ —

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Summary of Financial Statement Items Measured at Fair Value on Recurring Basis	Following is a summary of financial statement items that are measured at fair value on a recurring basis: September 30, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets: Short-term investments $ 26,736 $ — $ — $ 26,736 Mortgage-backed securities at fair value — 2,126,507 — 2,126,507 Mortgage loans acquired for sale at fair value — 1,942,335 7,097 1,949,432 Mortgage loans at fair value — 292,174 340,994 633,168 Excess servicing spread purchased from PFSI — — 223,275 223,275 Derivative assets: Interest rate lock commitments — — 2,317 2,317 CRT Agreements — — 126,354 126,354 Repurchase agreement derivatives — — 9,415 9,415 Forward purchase contracts — 1,761 — 1,761 Forward sale contracts — 19,238 — 19,238 MBS call options — 7 — 7 MBS put options — 2,302 — 2,302 Put options on interest rate futures 141 — — 141 Total derivative assets before netting 141 23,308 138,086 161,535 Netting — — — (17,958 ) Total derivative assets after netting 141 23,308 138,086 143,577 Firm commitment to purchase credit risk transfer security at fair value — — 18,749 18,749 Mortgage servicing rights at fair value — — 1,109,741 1,109,741 $ 26,877 $ 4,384,324 $ 1,837,942 $ 6,231,185 Liabilities: Asset-backed financing of a VIE at fair value $ — $ 278,113 $ — $ 278,113 Interest-only security payable at fair value — — 8,821 8,821 Derivative liabilities: Interest rate lock commitments — — 3,418 3,418 Forward purchase contracts — 11,964 — 11,964 Forward sales contracts — 1,719 — 1,719 Total derivative liabilities before netting — 13,683 3,418 17,101 Netting — — — (5,221 ) Total derivative liabilities after netting — 13,683 3,418 11,880 $ — $ 291,796 $ 12,239 $ 298,814 December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Assets: Short-term investments $ 18,398 $ — $ — $ 18,398 Mortgage-backed securities at fair value — 989,461 — 989,461 Mortgage loans acquired for sale at fair value — 1,261,380 8,135 1,269,515 Mortgage loans at fair value — 321,040 768,433 1,089,473 Excess servicing spread purchased from PFSI — — 236,534 236,534 Derivative assets: Interest rate lock commitments — — 4,859 4,859 CRT Agreements — — 98,640 98,640 Repurchase agreement derivatives — — 3,748 3,748 Forward purchase contracts — 4,343 — 4,343 Forward sale contracts — 387 — 387 MBS put options — 3,170 — 3,170 Put options on interest rate futures 656 — — 656 Total derivative assets before netting 656 7,900 107,247 115,803 Netting — — — (1,922 ) Total derivative assets after netting 656 7,900 107,247 113,881 Mortgage servicing rights at fair value — — 91,459 91,459 $ 19,054 $ 2,579,781 $ 1,211,808 $ 3,808,721 Liabilities: Asset-backed financing of a VIE at fair value $ — $ 307,419 $ — $ 307,419 Interest-only security payable at fair value — — 7,070 7,070 Derivative liabilities: Interest rate lock commitments — — 227 227 Forward purchase contracts — 248 — 248 Forward sales contracts — 2,830 — 2,830 Total derivative liabilities before netting — 3,078 227 3,305 Netting — — — (1,999 ) Total derivative liabilities after netting — 3,078 227 1,306 $ — $ 310,497 $ 7,297 $ 315,795
Summary of Changes in Items Measured Using Level 3 Inputs on Recurring Basis	The following is a summary of changes in items measured at fair value on a recurring basis using Level 3 inputs that are significant to the estimation of the fair values of the assets and liabilities at either the beginning or end of the years presented: Quarter ended September 30, 2018 Mortgage loans acquired for sale at fair value Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Firm commitment to purchase CRT security Mortgage servicing rights Total (in thousands) Assets: Balance, June 30, 2018 $ 6,540 $ 447,473 $ 229,470 $ 2,807 $ 119,169 $ 6,912 $ 4,426 $ 1,010,507 $ 1,827,304 Purchases and issuances 2,640 — — (3,699 ) — 5,671 — — 4,612 Repayments and sales (2,481 ) (98,622 ) (11,543 ) — (23,367 ) (3,131 ) — (100 ) (139,244 ) Capitalization of interest — 2,297 3,740 — — — — — 6,037 Capitalization of advances — 1,373 — — — — — — 1,373 ESS received pursuant to a recapture agreement with PFSI — — 499 — — — — — 499 Amounts received as proceeds from sales of mortgage loans — — — — — — 12,311 96,383 108,694 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — 4,407 — — — — — — 4,407 Other factors (324 ) (7,458 ) 1,109 (4,001 ) 30,552 (37 ) 2,012 2,951 24,804 (324 ) (3,051 ) 1,109 (4,001 ) 30,552 (37 ) 2,012 2,951 29,211 Transfers of mortgage loans to REO and real estate held for investment — (8,476 ) — — — — — — (8,476 ) Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2) 722 — — — — — — — 722 Transfers of interest rate lock commitments to mortgage loans acquired for sale — — — 3,792 — — — — 3,792 Balance, September 30, 2018 $ 7,097 $ 340,994 $ 223,275 $ (1,101 ) $ 126,354 $ 9,415 $ 18,749 $ 1,109,741 $ 1,834,524 Changes in fair value recognized during the quarter relating to assets still held at September 30, 2018 $ (257 ) $ (6,711 ) $ 1,109 $ (1,101 ) $ 7,185 $ — $ 2,012 $ 2,951 $ 5,188 (1) For the purpose of this table, the interest rate lock commitment (“IRLC”) asset and liability positions are shown net. (2) During the quarter ended September 30, 2018, the Manager identified certain “Level 2” fair value mortgage loans acquired for sale that were not saleable into the prime mortgage market and therefore transferred them to “Level 3”. Quarter ended September 30, 2018 Interest-only security payable (in thousands) Liabilities: Balance, June 30, 2018 $ 7,652 Changes in fair value included in income arising from: Changes in instrument-specific credit risk — Other factors 1,169 1,169 Balance, September 30, 2018 $ 8,821 Changes in fair value recognized during the quarter relating to liability outstanding at September 30, 2018 $ 1,169 Quarter ended September 30, 2017 Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Mortgage servicing rights Total (in thousands) Assets: Balance, June 30, 2017 $ 1,184,620 $ 261,796 $ 395 $ 52,716 $ — $ 77,624 $ 1,577,151 Purchases and issuances — — 9,264 — 181 10 9,455 Repayments and sales (156,821 ) (13,410 ) — (10,798 ) — — (181,029 ) Capitalization of interest 7,020 3,998 — — — — 11,018 Capitalization of advances 4,611 — — — — — 4,611 ESS received pursuant to a recapture agreement with PFSI — 1,207 — — — — 1,207 Amounts received as proceeds from sales of mortgage loans — — — — — 8,655 8,655 Changes in fair value included in income arising from: Changes in instrument-specific credit risk 6,035 — — — — — 6,035 Other factors (2,758 ) (4,828 ) 15,430 14,960 — (3,977 ) 18,827 3,277 (4,828 ) 15,430 14,960 — (3,977 ) 24,862 Transfers of mortgage loans to REO and real estate held for investment (26,705 ) — — — — — (26,705 ) Transfers of interest rate lock commitments to mortgage loans acquired for sale — — (23,814 ) — — — (23,814 ) Balance, September 30, 2017 $ 1,016,002 $ 248,763 $ 1,275 $ 56,878 $ 181 $ 82,312 $ 1,405,411 Changes in fair value recognized during the quarter relating to assets still held at September 30, 2017 $ (7,302 ) $ (4,828 ) $ 1,275 $ 4,162 $ — $ (3,977 ) $ (10,670 ) (1) For the purpose of this table, the IRLC asset and liability positions are shown net. Quarter ended September 30, 2017 Interest-only security payable (in thousands) Liabilities: Balance, June 30, 2017 $ 6,577 Changes in fair value included in income arising from: Changes in instrument-specific credit risk — Other factors (191 ) (191 ) Balance, September 30, 2017 $ 6,386 Changes in fair value recognized during the quarter relating to liability outstanding at September 30, 2017 $ (191 ) Nine months ended September 30, 2018 Mortgage loans acquired for sale at fair value Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Firm commitment to purchase CRT security Mortgage servicing rights Total (in thousands) Assets: Balance, December 31, 2017 $ 8,135 $ 768,433 $ 236,534 $ 4,632 $ 98,640 $ 3,748 $ — $ 91,459 $ 1,211,581 Cumulative effect of a change in accounting principle — Adoption of fair value accounting for mortgage servicing rights — — — — — — — 773,035 773,035 Balance, January 1, 2018 8,135 768,433 236,534 4,632 98,640 3,748 — 864,494 1,984,616 Purchases and issuances 8,243 — — 2,140 — 11,411 — — 21,794 Repayments and sales (10,441 ) (381,646 ) (35,852 ) — (64,907 ) (5,626 ) — (100 ) (498,572 ) Capitalization of interest — 6,543 11,584 — — — — — 18,127 Capitalization of advances — 4,733 — — — — — — 4,733 ESS received pursuant to a recapture agreement with PFSI — — 1,983 — — — — — 1,983 Amounts received as proceeds from sales of mortgage loans — — — — — — 16,737 228,337 245,074 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — 6,864 — — — — — — 6,864 Other factors (176 ) (24,566 ) 9,026 (28,571 ) 92,621 (118 ) 2,012 17,010 67,238 (176 ) (17,702 ) 9,026 (28,571 ) 92,621 (118 ) 2,012 17,010 74,102 Transfers of mortgage loans to REO and real estate held for investment — (39,367 ) — — — — — — (39,367 ) Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2) 1,336 — — — — — — — 1,336 Transfers of interest rate lock commitments to mortgage loans acquired for sale — — — 20,698 — — — — 20,698 Balance, September 30, 2018 $ 7,097 $ 340,994 $ 223,275 $ (1,101 ) $ 126,354 $ 9,415 $ 18,749 $ 1,109,741 $ 1,834,524 Changes in fair value recognized during the period relating to assets still held at September 30, 2018 $ (330 ) $ (18,170 ) $ 9,026 $ (1,101 ) $ 27,714 $ 77 $ 2,012 $ 17,010 $ 36,238 (1) For the purpose of this table, the IRLC asset and liability positions are shown net. (2) During the nine months ended September 30, 2018, the Manager identified certain “Level 2” fair value mortgage loans acquired for sale that were not saleable into the prime mortgage market and therefore transferred them to “Level 3”. Nine months ended September 30, 2018 Interest-only security payable (in thousands) Liabilities: Balance, December 31, 2017 $ 7,070 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — Other factors 1,751 1,751 Balance, September 30, 2018 $ 8,821 Changes in fair value recognized during the period relating to liability outstanding at September 30, 2018 $ 1,751 Nine months ended September 30, 2017 Mortgage loans at fair value Excess servicing spread Interest rate lock commitments (1) CRT Agreements Repurchase agreement derivatives Mortgage servicing rights Total (in thousands) Assets: Balance, December 31, 2016 $ 1,354,572 $ 288,669 $ 3,777 $ 15,610 $ — $ 64,136 $ 1,726,764 Purchases and issuances — — 26,185 — 181 79 26,445 Repayments and sales (302,829 ) (42,320 ) — (27,595 ) — — (372,744 ) Capitalization of interest 27,737 13,011 — — — — 40,748 Capitalization of advances 17,759 — — — — — 17,759 ESS received pursuant to a recapture agreement with PFSI — 4,160 — — — — 4,160 Amounts received as proceeds from sales of mortgage loans — — — — — 28,467 28,467 Changes in fair value included in income arising from: Changes in instrument-specific credit risk 23,498 — — — — — 23,498 Other factors (15,975 ) (14,757 ) 43,946 68,863 — (10,370 ) 71,707 7,523 (14,757 ) 43,946 68,863 — (10,370 ) 95,205 Transfers of mortgage loans to REO and real estate held for investment (88,760 ) — — — — — (88,760 ) Transfers of interest rate lock commitments to mortgage loans acquired for sale — — (72,633 ) — — — (72,633 ) Balance, September 30, 2017 $ 1,016,002 $ 248,763 $ 1,275 $ 56,878 $ 181 $ 82,312 $ 1,405,411 Changes in fair value recognized during the period relating to assets still held at September 30, 2017 $ (6,650 ) $ (14,757 ) $ 1,275 $ 41,268 $ — $ (10,370 ) $ 10,766 (1) For the purpose of this table, the IRLC asset and liability positions are shown net. Nine months ended September 30, 2017 Interest-only security payable (in thousands) Liabilities: Balance, December 31, 2016 $ 4,114 Changes in fair value included in income arising from: Changes in instrument- specific credit risk — Other factors 2,272 2,272 Balance, September 30, 2017 6,386 Changes in fair value recognized during the period relating to liability outstanding at September 30, 2017 $ 2,272
Fair Values and Related Principal Amounts Due upon Maturity of Mortgage Loans Accounted for Under Fair Value Option	Following are the fair values and related principal amounts due upon maturity of mortgage loans accounted for under the fair value option (including mortgage loans acquired for sale, mortgage loans held in a consolidated VIE, and distressed mortgage loans at fair value): September 30, 2018 December 31, 2017 Fair value Principal amount due upon maturity Difference Fair value Principal amount due upon maturity Difference (in thousands) Mortgage loans acquired for sale at fair value: Current through 89 days delinquent $ 1,949,285 $ 1,900,556 $ 48,729 $ 1,268,121 $ 1,221,125 $ 46,996 90 or more days delinquent: Not in foreclosure 147 187 (40 ) 950 1,120 (170 ) In foreclosure — — — 444 496 (52 ) 147 187 (40 ) 1,394 1,616 (222 ) $ 1,949,432 $ 1,900,743 $ 48,689 $ 1,269,515 $ 1,222,741 $ 46,774 Mortgage loans at fair value: Mortgage loans held in a consolidated VIE: Current through 89 days delinquent $ 292,174 $ 299,843 $ (7,669 ) $ 321,040 $ 316,684 $ 4,356 90 or more days delinquent: Not in foreclosure — — — — — — In foreclosure — — — — — — — — — — — — 292,174 299,843 (7,669 ) 321,040 316,684 4,356 Distressed mortgage loans at fair value: Current through 89 days delinquent 200,176 261,808 (61,632 ) 414,785 519,009 (104,224 ) 90 or more days delinquent: Not in foreclosure 66,791 113,308 (46,517 ) 166,749 257,038 (90,289 ) In foreclosure 74,027 113,067 (39,040 ) 186,899 267,911 (81,012 ) 140,818 226,375 (85,557 ) 353,648 524,949 (171,301 ) 340,994 488,183 (147,189 ) 768,433 1,043,958 (275,525 ) $ 633,168 $ 788,026 $ (154,858 ) $ 1,089,473 $ 1,360,642 $ (271,169 )
Summary of Changes in Fair Value Included in Current Period Income	Following are the changes in fair value included in current period income by consolidated statement of income line item for financial statement items accounted for under the fair value option: Quarter ended September 30, 2018 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — (19,030 ) (1,229 ) (20,259 ) Mortgage loans acquired for sale at fair value — 751 — — 751 Mortgage loans at fair value — — (6,681 ) 2,458 (4,223 ) ESS at fair value — — 1,109 3,740 4,849 Firm commitment to purchase credit risk transfer security at fair value — 12,311 2,012 — 14,323 MSRs at fair value 2,951 — — — 2,951 $ 2,951 $ 13,062 $ (22,590 ) $ 4,969 $ (1,608 ) Liabilities: Interest-only security payable at fair value $ — $ — $ (1,169 ) $ — $ (1,169 ) Asset-backed financing of a VIE at fair value — — 3,516 (201 ) 3,315 $ — $ — $ 2,347 $ (201 ) $ 2,146 Quarter ended September 30, 2017 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — 5,001 (1,481 ) 3,520 Mortgage loans acquired for sale at fair value — 32,935 — — 32,935 Mortgage loans at fair value — — 5,415 7,617 13,032 ESS at fair value — — (4,828 ) 3,998 (830 ) MSRs at fair value (3,977 ) — — — (3,977 ) $ (3,977 ) $ 32,935 $ 5,588 $ 10,134 $ 44,680 Liabilities: Interest-only security payable at fair value $ — $ — $ 191 $ — $ 191 Asset-backed financing of a VIE at fair value — — (2,158 ) (735 ) (2,893 ) $ — $ — $ (1,967 ) $ (735 ) $ (2,702 ) Nine months ended September 30, 2018 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — (50,288 ) (2,623 ) (52,911 ) Mortgage loans acquired for sale at fair value — (27,397 ) — — (27,397 ) Mortgage loans at fair value — — (29,694 ) 6,509 (23,185 ) ESS at fair value — — 9,026 11,584 20,610 Firm commitment to purchase credit risk transfer security at fair value — 16,737 2,012 — 18,749 MSRs at fair value 17,010 — — — 17,010 $ 17,010 $ (10,660 ) $ (68,944 ) $ 15,470 $ (47,124 ) Liabilities: Interest-only security payable at fair value $ — $ — $ (1,751 ) $ — $ (1,751 ) Asset-backed financing of a VIE at fair value — — 12,658 (74 ) 12,584 $ — $ — $ 10,907 $ (74 ) $ 10,833 Nine months ended September 30, 2017 Net mortgage loan servicing fees Net gain on mortgage loans acquired for sale Net gain (loss) on investments Net interest income Total (in thousands) Assets: Short-term investments at fair value $ — $ — $ — $ — $ — Mortgage-backed securities at fair value — — 9,168 (4,276 ) 4,892 Mortgage loans acquired for sale at fair value — 83,839 — — 83,839 Mortgage loans at fair value — — 13,832 29,195 43,027 ESS at fair value — — (14,757 ) 13,011 (1,746 ) MSRs at fair value (10,370 ) — — — (10,370 ) $ (10,370 ) $ 83,839 $ 8,243 $ 37,930 $ 119,642 Liabilities: Interest-only security payable at fair value $ — $ — $ (2,272 ) $ — $ (2,272 ) Asset-backed financing of a VIE at fair value — — (5,581 ) (1,807 ) (7,388 ) $ — $ — $ (7,853 ) $ (1,807 ) $ (9,660 )
Summary of Carrying Value of Financial Statement Items Re-measured at Fair Value on Nonrecurring Basis	Following is a summary of the carrying value at year end for financial statement items that were re-measured at fair value on a nonrecurring basis during the periods presented: September 30, 2018 Level 1 Level 2 Level 3 Total (in thousands) Real estate acquired in settlement of loans $ — $ — $ 37,722 $ 37,722 $ — $ — $ 37,722 $ 37,722 December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Real estate acquired in settlement of loans $ — $ — $ 71,380 $ 71,380 MSRs at lower of amortized cost or fair value — — 312,995 312,995 $ — $ — $ 384,375 $ 384,375
Summary of Changes in Fair Value Recognized in Assets that Remeasured at Fair Value on a Nonrecurring Basis	The following table summarizes the fair value changes recognized during the period on assets held at period end that were remeasured at fair value on a nonrecurring basis: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Real estate asset acquired in settlement of loans $ (2,285 ) $ (5,666 ) $ (6,209 ) $ (7,454 ) MSRs at lower of amortized cost or fair value — (1,702 ) — (4,287 ) $ (2,285 ) $ (7,368 ) $ (6,209 ) $ (11,741 )
Quantitative Summary of Key Inputs Used in Valuation of Level 3 Mortgage Loans at Fair Value	Following is a quantitative summary of key inputs used in the valuation of the Company’s “Level 3” mortgage loans at fair value: Key inputs (1) September 30, 2018 December 31, 2017 Discount rate Range 2.8% – 16.7% 2.9% – 15.0% Weighted average 7.3% 6.9% Twelve-month projected housing price index change Range 3.5% – 4.4% 3.6% – 4.6% Weighted average 4.1% 4.4% Prepayment speed (2) Range 2.5% – 8.1% 3.2% – 11.0% Weighted average 4.1% 4.2% Total prepayment speed (3) Range 10.4% – 22.3% 10.8% – 23.8% Weighted average 15.6% 16.5% (1) Weighted-average inputs are based on fair value amounts of the mortgage loans. (1) Prepayment speed is measured using Life Voluntary Conditional Prepayment Rate (“CPR”). (3) Total prepayment speed is measured using Life Total CPR.
Summary of Key Inputs Used in Determining Fair Value of ESS	Following are the key inputs used in determining the fair value of ESS: Key inputs (1) September 30, 2018 December 31, 2017 UPB of underlying mortgage loans (in thousands) $ 24,058,366 $ 27,217,199 Average servicing fee rate (in basis points) 34 34 Average ESS rate (in basis points) 19 19 Pricing spread (2) Range 3.4% - 3.9% 3.8% - 4.3% Weighted average 3.7% 4.1% Annual total prepayment speed (3) Range 7.5% - 38.4% 8.4% - 41.4% Weighted average 9.0% 10.8% Life (in years) Range 1.4 - 8.0 1.4 - 7.7 Weighted average 7.1 6.5 (1) Weighted-average inputs are based on UPB of underlying amounts of mortgage loans. (2) Pricing spread represents a margin that is applied to a reference interest rate’s forward rate curve to develop periodic discount rates. The Company applies a pricing spread to the United States Dollar London Interbank Offered Rate (“LIBOR”) curve for purposes of discounting cash flows relating to ESS. (3) Prepayment speed is measured using Life Total CPR.
Schedule of Key Inputs Used in Determining Fair Value of Firm Commitment to Purchase Credit Risk Transfer Security	The Company categorizes its firm commitment to purchase credit risk transfer securities as a “Level 3” fair value asset. The fair value of the firm commitment is estimated using a discounted cash flow approach to estimate the fair value of the credit risk transfer security to be purchased related to the loans subject to the commitment. Key inputs used in the estimation of fair value of the firm commitment are the discount rate and the voluntary and involuntary prepayment speeds of the reference mortgage loans. The firm commitment to purchase credit transfer securities is recognized initially as a component of Gain on sale of mortgage loans acquired for sale Net gain (loss) on investments Key inputs September 30, 2018 Discount rate 8.2% Voluntary prepayment speed (1) 12.0% Involuntary prepayment speed (2) 0.1% (1) Voluntary prepayment speed is measured using Life Voluntary CPR. (2) Involuntary prepayment speed is measured using Life Involuntary CPR.
Quantitative Summary of Key Unobservable Inputs Used in Valuation of Interest Rate Lock Commitments	Following is a quantitative summary of key unobservable inputs used in the valuation of IRLCs: Key inputs (1) September 30, 2018 December 31, 2017 Pull-through rate Range 43.8% – 100% 58.0% - 100% Weighted average 92.6% 90.3% MSR value expressed as Servicing fee multiple Range 2.5 - 5.9 2.1 - 5.8 Weighted average 4.7 4.9 Percentage of UPB Range 0.8% – 2.8% 0.0% - 2.4% Weighted average 1.4% 1.3% (1) Weighted-average inputs are based on notional amounts.
Quantitative Summary of Key Unobservable Inputs Used in Valuation of Non-securitized CRT Agreements	Following is a quantitative summary of key unobservable inputs used in the valuation of non-securitized CRT Agreements: Key inputs (1) September 30, 2018 December 31, 2017 Discount rate Range 5.8% – 6.7% 5.1% – 6.2% Weighted average 6.2% 5.6% Voluntary prepayment speed (2) Range 7.5% – 8.7% 12.1% – 15.0% Weighted average 8.1% 13.0% Involuntary prepayment speed (3) Range 0.2% – 0.3% 0.3% – 0.3% Weighted average 0.3% 0.3% (1) Weighted-average inputs are based on fair value amounts of the CRT Agreements. (2) Voluntary prepayment speed is measured using Life Voluntary CPR. (3) Involuntary prepayment speed is measured using Life Involuntary CPR.
Key Assumptions Used in Determining Fair Value of MSRs at Time of Initial Recognition	Following are the key inputs used in determining the fair value of MSRs at the time of initial recognition: Quarter ended September 30, 2018 2017 Fair value Fair value Amortized cost (MSR recognized and UPB of underlying mortgage loan amounts in thousands) MSR recognized $ 96,383 $ 8,655 $ 74,183 Key inputs (1) UPB of underlying mortgage loans $ 8,290,310 $ 794,770 $ 6,050,337 Weighted-average annual servicing fee rate (in basis points) 25 25 25 Pricing spread (2) Range 7.3% – 12.9% 7.6% – 7.6% 7.6% – 12.6% Weighted average 7.3% 7.6% 7.6% Annual total prepayment speed (3) Range 3.5% – 34.6% 8.3% – 29.5% 3.5% – 31.1% Weighted average 10.6% 10.5% 8.1% Life (in years) Range 2.3 - 11.7 2.8 - 8.5 2.6 - 11.2 Weighted average 7.3 7.4 8.4 Annual per-loan cost of servicing Range $77 - $79 $79 - $79 $79 - $79 Weighted average $79 $79 $79 (1) Weighted-average inputs are based on UPB of the underlying mortgage loans. (2) The Company applies a pricing spread to the United States Dollar LIBOR curve for purposes of discounting cash flows relating to MSRs. (3) Prepayment speed is measured using Life Total CPR. Nine months ended September 30, 2018 2017 Fair value Fair value Amortized cost (MSR recognized and UPB of underlying mortgage loan amounts in thousands) MSR recognized $ 228,337 $ 28,467 $ 178,894 Key inputs (1) UPB of underlying mortgage loans $ 18,687,615 $ 2,613,258 $ 14,624,151 Weighted-average annual servicing fee rate (in basis points) 26 25 25 Pricing spread (2) Range 7.3% – 12.9% 7.6% – 7.6% 7.6% – 12.6% Weighted average 7.4% 7.6% 7.6% Annual total prepayment speed (3) Range 3.2% – 34.6% 7.9% – 29.5% 3.2% – 31.1% Weighted average 9.6% 10.7% 8.1% Life (in years) Range 2.3 - 11.9 2.8 - 8.5 2.6 - 11.9 Weighted average 7.7 7.3 8.3 Annual per-loan cost of servicing Range $77 - $79 $79 - $79 $79 - $79 Weighted average $79 $79 $79 (1) Weighted-average inputs are based on the UPB of the underlying mortgage loans. (2) The Company applies a pricing spread to the United States Dollar LIBOR curve for purposes of discounting cash flows relating to MSRs. (3) Prepayment speed is measured using Life Total CPR.
Quantitative Summary of Key Assumptions Used in Valuation of MSRs as of Dates Presented, and Effect on Estimated Fair Value from Adverse Changes in Those Inputs	Following is a quantitative summary of key inputs used in the valuation of MSRs as of the dates presented, and the effect on the fair value from adverse changes in those inputs: September 30, 2018 December 31, 2017 Fair value Fair value Amortized cost (Carrying value, UPB of underlying mortgage loans and effect on fair value amounts in thousands) Carrying value $ 1,109,741 $ 91,459 $ 753,322 Key inputs (1): UPB of underlying mortgage loans $ 84,351,431 $ 8,273,696 $ 63,853,606 Weighted-average annual servicing fee rate (in basis points) 25 25 25 Weighted-average note interest rate 4.1% 4.7% 3.9% Pricing spread (2) Range 7.3% – 12.9% 7.6% – 12.6% 7.6% – 13.1% Weighted average 7.3% 7.6% 7.6% Effect on fair value of (3): 5% adverse change $ (16,686 ) $ (1,347 ) $ (11,848 ) 10% adverse change $ (32,897 ) $ (2,655 ) $ (23,352 ) 20% adverse change $ (63,970 ) $ (5,162 ) $ (45,379 ) Prepayment speed (4) Range 6.2% – 24.3% 7.3% – 20.9% 7.1% – 27.1% Weighted average 7.6% 11.1% 8.4% Life (in years) Range 2.9 - 8.5 3.1 - 6.8 2.9 - 8.0 Weighted average 8.1 6.8 7.6 Effect on fair value of (3): 5% adverse change $ (15,209 ) $ (1,954 ) $ (12,267 ) 10% adverse change $ (29,926 ) $ (3,827 ) $ (24,120 ) 20% adverse change $ (57,978 ) $ (7,352 ) $ (46,668 ) Annual per-loan cost of servicing Range $78 - $79 $77 – $79 $78 – $79 Weighted average $79 $79 $79 Effect on fair value of (3): 5% adverse change $ (7,834 ) $ (744 ) $ (5,721 ) 10% adverse change $ (15,668 ) $ (1,488 ) $ (11,441 ) 20% adverse change $ (31,337 ) $ (2,976 ) $ (22,883 ) (1) Weighted-average inputs are based on the UPB of underlying mortgage loans. (2) The Company applies a pricing spread to the United States Dollar LIBOR curve for purposes of discounting cash flows relating to MSRs. (3) For MSRs carried at fair value, an adverse change in one of the above-mentioned key inputs is expected to result in a recognized reduction in fair value which would be recorded in income. For MSRs carried at lower of amortized cost or fair value, an adverse change in one of the above-mentioned key inputs may have resulted in recognition of MSR impairment. The extent of the recognized MSR impairment depended on the relationship of fair value to the carrying value of such MSRs. (4) Prepayment speed is measured using Life Total CPR.

Mortgage Backed Securities (Tab

Mortgage Backed Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Mortgage Backed Securities [Abstract]
Summary of Mortgage Backed Securities	Following is a summary of MBS: September 30, 2018 December 31, 2017 Principal balance Net premiums Accumulated valuation changes Fair value Principal balance Net premiums Accumulated valuation changes Fair value (in thousands) Agency: (1) Fannie Mae $ 1,592,192 $ 40,413 $ (46,691 ) $ 1,585,914 $ 774,473 $ 30,355 $ (7,975 ) $ 796,853 Freddie Mac 543,239 6,963 (9,609 ) 540,593 187,127 3,518 1,963 192,608 $ 2,135,431 $ 47,376 $ (56,300 ) $ 2,126,507 $ 961,600 $ 33,873 $ (6,012 ) $ 989,461 (1) All MBS are fixed-rate pass-through securities.

Mortgage Loans Acquired for S_2

Mortgage Loans Acquired for Sale at Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Mortgage Loans On Real Estate [Abstract]
Summary of Distribution of Company's Mortgage Loans Acquired for Sale at Fair Value	Mortgage loans acquired for sale at fair value is comprised of recently originated mortgage loans purchased by the Company for resale. Following is a summary of the distribution of the Company’s mortgage loans acquired for sale at fair value: Loan type September 30, 2018 December 31, 2017 (in thousands) Agency-eligible $ 1,708,928 $ 971,910 Held for sale to PLS — Government insured or guaranteed 217,334 279,571 Commercial real estate 8,500 9,898 Jumbo 7,573 — Repurchased pursuant to representations and warranties 7,097 8,136 $ 1,949,432 $ 1,269,515 Mortgage loans pledged to secure: Assets sold under agreements to repurchase $ 1,898,155 $ 1,201,992 Mortgage loan participation purchase and sale agreements 32,392 47,285 $ 1,930,547 $ 1,249,277

Mortgage Loans at Fair Value (T

Mortgage Loans at Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Distribution of Company's Mortgage Loans at Fair Value	Following is a summary of the distribution of the Company’s mortgage loans at fair value: September 30, 2018 December 31, 2017 Loan type Fair value Unpaid principal balance Fair value Unpaid principal balance (in thousands) Distressed mortgage loans: Nonperforming mortgage loans $ 140,818 $ 226,375 $ 353,648 $ 524,949 Performing mortgage loans: Interest rate step-up 125,063 170,066 189,724 242,335 Fixed interest rate 58,179 73,769 186,929 236,840 Adjustable-rate/hybrid 16,934 17,973 38,132 39,834 200,176 261,808 414,785 519,009 340,994 488,183 768,433 1,043,958 Fixed interest rate jumbo mortgage loans held in a VIE 292,174 299,843 321,040 316,684 $ 633,168 $ 788,026 $ 1,089,473 $ 1,360,642 Mortgage loans at fair value pledged to secure: Assets sold under agreements to repurchase $ 332,093 $ 760,853 Asset-backed financing of a VIE at fair value 292,174 321,040 $ 624,267 $ 1,081,893
Summary of Certain Concentrations of Credit Risk in Portfolio of Distressed Mortgage Loans at Fair Value	Following is a summary of certain concentrations of credit risk in the portfolio of distressed mortgage loans at fair value: Concentration September 30, 2018 December 31, 2017 (percentages are of fair value) Portion of mortgage loans originated between 2005 and 2007 71% 73% Mortgage loans with unpaid-principal balance-to-current -property-value in excess of 100% 31% 38% States contributing 5% or more of mortgage loans New York California Florida New Jersey New York California New Jersey Florida Massachusetts

Derivative Activities (Tables)

Derivative Activities (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Assets and Liabilities Recorded within Derivative Assets and Derivative Liabilities and Related Margin Deposits Recorded in Other Assets	The Company had the following derivative assets and liabilities recorded within Derivative assets Derivative liabilities Other September 30, 2018 December 31, 2017 Fair value Fair value Notional Derivative Derivative Notional Derivative Derivative Instrument amount assets liabilities amount assets liabilities (in thousands) Derivatives not designated as hedging instruments: Not subject to master netting arrangements: Interest rate lock commitments 1,682,007 $ 2,317 $ 3,418 1,250,803 $ 4,859 $ 227 CRT Agreements 30,648,306 126,354 — 26,845,392 98,640 — Repurchase agreement derivatives 9,415 — 3,748 — Subject to master netting agreements ─ for hedging purposes: Forward purchase contracts 3,350,125 1,761 11,964 1,996,235 4,343 248 Forward sale contracts 5,124,927 19,238 1,719 2,565,271 387 2,830 MBS put options 2,600,000 2,302 — 2,375,000 3,170 — MBS call options 750,000 7 — — — — Put options on interest rate futures 100,000 141 — 550,000 656 — Swap futures — — — 275,000 — — Bond futures 815,000 — — — — — Eurodollar future sale contracts 30,000 — — 937,000 — — Total derivative instruments before netting 161,535 17,101 115,803 3,305 Netting (17,958 ) (5,221 ) (1,922 ) (1,999 ) $ 143,577 $ 11,880 $ 113,881 $ 1,306 Margin deposits placed with (from) derivatives counterparties included in Other $ (12,736 ) $ 76 Derivative assets pledged to secure Assets sold under agreements to repurchase $ 27,710 $ 26,058
Summary of Net Derivative Assets	Following is a summary of net derivative assets: September 30, 2018 December 31, 2017 Gross amounts of recognized assets Gross amounts offset in the consolidated balance sheet Net amounts of assets presented in the consolidated balance sheet Gross amounts of recognized assets Gross amounts offset in the consolidated balance sheet Net amounts of assets presented in the consolidated balance sheet (in thousands) Derivative assets: Not subject to master netting arrangements: Interest rate lock commitments $ 2,317 $ — $ 2,317 $ 4,859 $ — $ 4,859 CRT Agreement derivatives 126,354 — 126,354 98,640 — 98,640 Repurchase agreement derivatives 9,415 — 9,415 3,748 — 3,748 138,086 — 138,086 107,247 — 107,247 Subject to master netting arrangements: Forward purchase contracts 1,761 — 1,761 4,343 — 4,343 Forward sale contracts 19,238 — 19,238 387 — 387 MBS call options 7 — 7 — — — MBS put options 2,302 — 2,302 3,170 — 3,170 Put options on interest rate futures 141 — 141 656 — 656 Netting — (17,958 ) (17,958 ) — (1,922 ) (1,922 ) 23,449 (17,958 ) 5,491 8,556 (1,922 ) 6,634 $ 161,535 $ (17,958 ) $ 143,577 $ 115,803 $ (1,922 ) $ 113,881
Summary of Derivative Assets, Financial Instruments and Collateral Held by Counterparty	The following table summarizes by significant counterparty the amount of derivative asset positions after considering master netting arrangements and financial instruments or cash pledged that do not meet the accounting guidance qualifying for setoff accounting: September 30, 2018 December 31, 2017 Net amount of assets presented in the Gross amounts not offset in the consolidated balance sheet Net amount of assets presented in the Gross amounts not offset in the consolidated balance sheet consolidated balance sheet Financial instruments Cash collateral received Net amount consolidated balance sheet Financial instruments Cash collateral received Net amount (in thousands) CRT Agreements $ 126,354 $ — $ — $ 126,354 $ 98,640 $ — $ — $ 98,640 Interest rate lock commitments 2,317 — — 2,317 4,859 — — 4,859 Deutsche Bank Securities LLC 9,415 — — 9,415 3,748 — — 3,748 Citigroup Global Markets Inc. 2,116 — — 2,116 429 — — 429 Wells Fargo Securities, LLC 950 — — 950 146 — — 146 J.P. Morgan Securities LLC 637 — — 637 2,020 — — 2,020 Bank of America, N.A. 627 — — 627 — — — — Goldman Sachs 558 — — 558 — — — — RJ O’Brien & Associates, LLC 141 — — 141 656 — — 656 Federal National Mortgage Association 9 — — 9 1,606 — — 1,606 Credit Suisse Securities (USA) LLC — — — — 809 — — 809 Morgan Stanley & Co. LLC — — — — 457 — — 457 Other 453 — — 453 511 — — 511 $ 143,577 $ — $ — $ 143,577 $ 113,881 $ — $ — $ 113,881
Schedule of Offsetting of Derivative Liabilities and Financial Liabilities	Following is a summary of net derivative liabilities and assets sold under agreements to repurchase. Assets sold under agreements to repurchase do not qualify for setoff accounting. September 30, 2018 December 31, 2017 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheet Net amounts of liabilities presented in the consolidated balance sheet Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheet Net amounts of liabilities presented in the consolidated balance sheet (in thousands) Derivative liabilities: Not subject to master netting arrangements: Interest rate lock commitments $ 3,418 $ — $ 3,418 $ 227 $ — $ 227 3,418 — 3,418 227 — 227 Subject to master netting arrangements: Forward purchase contracts 11,964 — 11,964 248 — 248 Forward sales contracts 1,719 — 1,719 2,830 — 2,830 Netting — (5,221 ) (5,221 ) — (1,999 ) (1,999 ) 13,683 (5,221 ) 8,462 3,078 (1,999 ) 1,079 17,101 (5,221 ) 11,880 3,305 (1,999 ) 1,306 Assets sold under agreements to repurchase: UPB 4,394,597 — 4,394,597 3,182,504 — 3,182,504 Unamortized debt issuance costs (97 ) — (97 ) (1,618 ) — (1,618 ) 4,394,500 — 4,394,500 3,180,886 — 3,180,886 $ 4,411,601 $ (5,221 ) $ 4,406,380 $ 3,184,191 $ (1,999 ) $ 3,182,192
Summary of Derivative Liabilities, Financial Liabilities and Collateral Pledged by Counterparty	The following table summarizes by significant counterparty the amount of derivative liabilities and assets sold under agreements to repurchase after considering master netting arrangements and financial instruments or cash pledged that do not meet the accounting guidance qualifying for setoff accounting. All assets sold under agreements to repurchase represent sufficient collateral or exceed the liability amount recorded on the consolidated balance sheet. September 30, 2018 December 31, 2017 Net amount of liabilities presented in the Gross amounts not offset in the consolidated balance sheet Net amount of liabilities presented in the Gross amounts not offset in the consolidated balance sheet consolidated balance sheet Financial instruments Cash collateral pledged Net amount consolidated balance sheet Financial instruments Cash collateral pledged Net amount (in thousands) Interest rate lock commitments $ 3,418 $ — $ — $ 3,418 $ 227 $ — $ — $ 227 Bank of America, N.A. 1,424,559 (1,424,559 ) — — 839,057 (838,771 ) — 286 Deutsche Bank Securities LLC 701,294 (701,294 ) — — 374,526 (374,526 ) — — Credit Suisse Securities (USA) LLC 683,565 (683,339 ) — 226 845,567 (845,567 ) — — J.P. Morgan Securities LLC 448,773 (448,773 ) — — 373,186 (373,186 ) — — Mizuho Securities 276,791 (276,791 ) — — — — — — Daiwa Capital Markets 262,985 (262,940 ) — 45 153,833 (153,730 ) — 103 Morgan Stanley & Co. LLC 224,035 (223,627 ) — 408 164,530 (164,530 ) — — Citigroup Global Markets Inc. 118,762 (116,091 ) — 2,671 235,541 (235,319 ) — 222 RBC Capital Markets, L.P. 95,027 (95,027 ) — — 92,014 (91,805 ) — 209 BNP Paribas 91,062 (91,062 ) — — 45,411 (45,411 ) — — Wells Fargo Securities, LLC 71,094 (71,094 ) — — 50,360 (50,360 ) — — Federal National Mortgage Association 4,350 — — 4,350 — — — — Barclays Capital Inc. 270 — — 270 9,374 (9,299 ) — 75 Other 492 — — 492 184 — — 184 Unamortized debt issuance costs (97 ) 97 — — (1,618 ) 1,618 — — $ 4,406,380 $ (4,394,500 ) $ — $ 11,880 $ 3,182,192 $ (3,180,886 ) $ — $ 1,306
Net Gains (Losses) Recognized on Derivative Financial Instruments	Following are the net gains (losses) recognized by the Company on derivative financial instruments and the consolidated statements of income line items where such gains and losses are included: Quarter ended September 30, Nine months ended September 30, Derivative activity Income statement line 2018 2017 2018 2017 (in thousands) Interest rate lock commitments Net gain on mortgage loans acquired for sale $ (7,700 ) $ 24,694 $ (26,431 ) $ 70,131 CRT agreements Net gain (loss) on investments $ 30,552 $ 14,960 $ 92,621 $ 68,863 Repurchase agreement derivatives Interest expense $ (37 ) $ — $ (118 ) $ — Hedged item: Interest rate lock commitments and mortgage loans acquired for sale Net gain on mortgage loans acquired for sale $ 15,584 $ (16,943 ) $ 56,818 $ (32,308 ) Mortgage servicing rights Net mortgage loan servicing fees $ (12,093 ) $ 4,576 $ (44,378 ) $ (1,731 ) Fixed-rate assets and LIBOR- indexed repurchase agreements Net gain (loss) on investments $ 691 $ (5,910 ) $ 1,029 $ (14,943 )
Derivative Arising From Derivative Contracts [Member]
Summary of Activity in Notional Amount for Derivative Contracts	The following tables summarize the notional amount activity for derivative contracts used to hedge the Company’s MBS financing, inventory of mortgage loans acquired for sale, mortgage loans at fair value held in a VIE, IRLCs and MSRs. Quarter ended September 30, 2018 Amount, Amount, beginning Dispositions/ end Instrument of quarter Additions expirations of quarter (in thousands) Forward purchase contracts 2,628,934 26,864,290 (26,143,099 ) 3,350,125 Forward sales contracts 3,793,355 36,205,542 (34,873,970 ) 5,124,927 MBS put options 1,550,000 1,050,000 — 2,600,000 MBS call options — 750,000 — 750,000 Call options on interest rate futures 50,000 200,000 (250,000 ) — Put options on interest rate futures 600,000 1,300,000 (1,800,000 ) 100,000 Bond futures 815,000 2,205,000 (2,205,000 ) 815,000 Eurodollar future sale contracts 35,000 5,000 (10,000 ) 30,000 Quarter ended September 30, 2017 Amount, Amount, beginning Dispositions/ end Instrument of quarter Additions expirations of quarter (in thousands) Forward purchase contracts 1,933,390 20,560,886 (20,895,864 ) 1,598,412 Forward sales contracts 3,644,636 27,214,513 (28,050,302 ) 2,808,847 MBS put options 1,475,000 3,200,000 (3,550,000 ) 1,125,000 MBS call options 200,000 275,000 (400,000 ) 75,000 Call options on interest rate futures 200,000 450,000 (400,000 ) 250,000 Put options on interest rate futures 925,000 2,500,000 (2,950,000 ) 475,000 Swap futures 175,000 100,000 — 275,000 Eurodollar future sale contracts 1,139,000 202,000 (303,000 ) 1,038,000 Treasury future buy contracts — 55,000 (55,000 ) — Treasury future sale contracts — 55,000 (55,000 ) — Nine months ended September 30, 2018 Amount, Amount, beginning Dispositions/ end Instrument of period Additions expirations of period (in thousands) Forward purchase contracts 1,996,235 67,406,528 (66,052,638 ) 3,350,125 Forward sales contracts 2,565,271 88,131,417 (85,571,761 ) 5,124,927 MBS put options 2,375,000 9,625,000 (9,400,000 ) 2,600,000 MBS call options — 750,000 — 750,000 Call options on interest rate futures — 525,000 (525,000 ) — Put options on interest rate futures 550,000 11,700,000 (12,150,000 ) 100,000 Swap futures 275,000 — (275,000 ) — Bond futures — 3,020,000 (2,205,000 ) 815,000 Eurodollar future sale contracts 937,000 119,597 (1,026,597 ) 30,000 Nine months ended September 30, 2017 Amount, Amount, beginning Dispositions/ end Instrument of period Additions expirations of period (in thousands) Forward purchase contracts 4,840,707 54,953,063 (58,195,358 ) 1,598,412 Forward sales contracts 6,148,242 73,030,446 (76,369,841 ) 2,808,847 MBS put options 925,000 5,125,000 (4,925,000 ) 1,125,000 MBS call option 750,000 475,000 (1,150,000 ) 75,000 Call options on interest rate futures 200,000 575,000 (525,000 ) 250,000 Put options on interest rate futures 550,000 5,875,000 (5,950,000 ) 475,000 Swap futures 150,000 950,000 (825,000 ) 275,000 Eurodollar future sale contracts 1,351,000 303,000 (616,000 ) 1,038,000 Treasury future buy contracts — 110,700 (110,700 ) — Treasury future sale contracts — 110,700 (110,700 ) —

Real Estate Acquired in Settl_2

Real Estate Acquired in Settlement of Loans (Tables)	9 Months Ended
	Sep. 30, 2018
Banking And Thrift [Abstract]
Summary of Financial Information Relating to REO	Following is a summary of financial information relating to REO: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance at beginning of period $ 109,271 $ 207,034 $ 162,865 $ 274,069 Transfers: From mortgage loans at fair value and advances 7,508 22,951 26,229 76,981 To real estate held for investment (559 ) (2,555 ) (4,123 ) (14,300 ) From real estate held for investment 655 — 1,112 — Results of REO: Valuation adjustments, net (3,323 ) (6,423 ) (13,990 ) (21,749 ) Gain on sale, net 3,013 3,280 8,157 10,895 (310 ) (3,143 ) (5,833 ) (10,854 ) Sales (20,960 ) (39,253 ) (84,645 ) (140,862 ) Balance at end of period $ 95,605 $ 185,034 $ 95,605 $ 185,034 September 30, 2018 December 31, 2017 (in thousands) REO pledged to secure assets sold under agreements to repurchase $ 43,970 $ 76,037 REO held in a consolidated subsidiary whose stock is pledged to secure financings of such properties 25,429 48,495 $ 69,399 $ 124,532

Mortgage Servicing Rights (Tabl

Mortgage Servicing Rights (Tables)	9 Months Ended
	Sep. 30, 2018
Summary of MSRs Carried at Fair Value	Following is a summary of MSRs carried at fair value: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance at beginning of period $ 1,010,507 $ 77,624 $ 91,459 $ 64,136 Transfer of mortgage servicing rights from mortgage servicing rights carried at lower of amortized cost or fair value pursuant to a change in accounting principle — — 773,035 — Balance after reclassification 1,010,507 77,624 864,494 64,136 Purchases — 10 — 79 Sales (100 ) — (100 ) — MSRs resulting from mortgage loan sales 96,383 8,655 228,337 28,467 Changes in fair value: Due to changes in valuation inputs used in valuation model (1) 33,004 (2,628 ) 101,699 (6,956 ) Other changes in fair value (2) (30,053 ) (1,349 ) (84,689 ) (3,414 ) 2,951 (3,977 ) 17,010 (10,370 ) Balance at end of period $ 1,109,741 $ 82,312 $ 1,109,741 $ 82,312 September 30, 2018 December 31, 2017 (in thousands) Fair value of mortgage servicing rights pledged to secure Assets sold under agreements to repurchase and (3) $ 1,090,406 $ 90,284 (1) Principally reflects changes in pricing spread (discount rate) and prepayment speed inputs, primarily due to changes in market interest rates. (2) Represents changes due to realization of expected cash flows. (3) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable Notes Payable
Summary of MSRs Carried at Lower of Amortized Cost or Fair Value	Following is a summary of MSRs carried at lower of amortized cost or fair value: Quarter ended September 30, Nine months ended September 30, 2017 2018 2017 (in thousands) Amortized Cost: Balance at beginning of period $ 673,433 $ 772,870 $ 606,103 Transfer of mortgage servicing right to mortgage servicing rights carried at fair value pursuant to a change in accounting principle — (772,870 ) — Balance after reclassification 673,433 — 606,103 MSRs resulting from mortgage loan sales 74,183 — 178,894 Amortization (21,634 ) — (59,015 ) Balance at end of period 725,982 — 725,982 Valuation Allowance: Balance at beginning of period (16,257 ) (19,548 ) (13,672 ) Reduction resulting from change in accounting principle — 19,548 — Balance after reclassification (16,257 ) — (13,672 ) Additions to valuation allowance (1,702 ) — (4,287 ) Balance at end of period (17,959 ) — (17,959 ) MSRs, net $ 708,023 $ — $ 708,023 Fair value at beginning of period $ 682,437 $ 626,334 Fair value at end of period $ 728,828 December 31, 2017 (in thousands) MSRs carried at lower of cost or fair value pledged to secure: Assets sold under agreements to repurchase $ 584,762 Notes payable 156,846 $ 741,608
Mortgage service rights [Member]
Summary of Net Mortgage Loan Servicing Fees Relating to MSRs	Servicing fees relating to MSRs are recorded in Net mortgage loan servicing fees Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Contractually-specified servicing fees $ 49,864 $ 42,237 $ 147,262 $ 119,223 Ancillary and other fees: Late charges 252 173 685 536 Other 2,859 1,870 5,988 4,110 $ 52,975 $ 44,280 $ 153,935 $ 123,869

Assets Sold Under Agreements _2

Assets Sold Under Agreements to Repurchase (Tables)	9 Months Ended
	Sep. 30, 2018
Summary of Financial Information Relating to Assets Sold under Agreements to Repurchase	Following is a summary of financial information relating to assets sold under agreements to repurchase: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average interest rate (1) 3.19 % 2.72 % 3.12 % 2.57 % Average balance $ 4,072,301 $ 3,474,903 $ 3,573,805 $ 3,388,626 Total interest expense (2) $ 29,725 $ 26,157 $ 79,705 $ 72,280 Maximum daily amount outstanding $ 5,091,893 $ 3,973,869 $ 5,677,797 $ 4,083,326 (1) Excludes the effect of amortization of net debt issuance premiums of $3.1 million and $4.8 million for the quarter and nine months ended September 30, 2018, respectively, and net debt issuance costs of $1.9 million and $6.1 million for the quarter and nine months ended September 30, 2017, respectively. (2) The Company’s interest expense relating to assets sold under agreements to repurchase for the quarter and nine months ended September 30, 2018 includes recognition of incentives it received for financing certain of its mortgage loans acquired for sale satisfying certain consumer debt relief characteristics under a master repurchase agreement. During the quarter and nine months ended September 30, 2018, the Company recognized $5.0 million and $11.0 million, respectively, in such incentives as a reduction of interest expense. The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity. September 30, 2018 December 31, 2017 (dollars in thousands) Carrying value: Unpaid principal balance $ 4,394,597 $ 3,182,504 Unamortized debt issuance costs and premiums, net (97 ) (1,618 ) $ 4,394,500 $ 3,180,886 Weighted-average interest rate 3.23 % 2.77 % Available borrowing capacity (1): Committed $ 564,023 $ 749,650 Uncommitted 1,947,494 2,030,607 $ 2,511,517 $ 2,780,257 Margin deposits placed with counterparties included in Other $ 42,550 $ 28,154 Assets securing agreements to repurchase: Mortgage-backed securities $ 2,126,507 $ 989,461 Mortgage loans acquired for sale at fair value $ 1,898,155 $ 1,201,992 Mortgage loans at fair value $ 332,093 $ 760,853 CRT Agreements: Deposits securing CRT agreements $ 378,090 $ 400,778 Derivative assets $ 27,710 $ 26,058 Real estate acquired in settlement of loans $ 69,399 $ 124,532 Real estate held for investment $ 31,795 $ 31,128 MSRs (2) $ 1,090,406 $ 651,575 (1) The amount the Company is able to borrow under asset repurchase agreements is tied to the fair value of unencumbered assets eligible to secure those agreements and the Company’s ability to fund the agreements’ margin requirements relating to the assets financed. (2) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable Notes Payable
Summary of Maturities of Outstanding Assets Sold under Agreements to Repurchase by Facility Maturity Date	Following is a summary of maturities of outstanding assets sold under agreements to repurchase by facility maturity date: Remaining maturity at September 30, 2018 Contractual balance (in thousands) Within 30 days $ 2,462,431 Over 30 to 90 days — Over 90 days to 180 days 10,328 Over 180 days to 1 year 1,815,302 Over one year to two years 106,536 $ 4,394,597 Weighted average maturity (in months) 3.9
Summary of Assets Sold under Agreements to Repurchase by Counterparty	Securities sold under agreements to repurchase Counterparty Amount at risk Weighted average maturity (in thousands) JPMorgan Chase & Co. $ 20,251 October 26, 2018 Bank of America, N.A. $ 47,090 October 21, 2018 Daiwa Capital Markets America Inc. $ 16,385 October 19, 2018 Mizuho Securities $ 8,634 October 10, 2018 Wells Fargo, N.A. $ 4,034 October 16, 2018
CRT Agreements sold under agreements to repurchase [Member]
Summary of Assets Sold under Agreements to Repurchase by Counterparty	CRT Agreements sold under agreements to repurchase Counterparty Amount at risk Weighted average maturity (in thousands) Credit Suisse First Boston Mortgage Capital LLC $ 50,793 October 10, 2018 Bank of America, N.A. $ 25,475 October 19, 2018 BNP Paribas Corporate & Institutional Banking $ 17,009 October 22, 2018
Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Summary of Assets Sold under Agreements to Repurchase by Counterparty	Mortgage loans, REO and MSRs sold under agreements to repurchase Counterparty Amount Weighted-average maturity Facility maturity (in thousands) Credit Suisse First Boston Mortgage Capital LLC $ 696,567 December 17, 2018 April 26, 2019 JPMorgan Chase & Co. $ 4,354 November 17, 2018 October 11, 2019 JPMorgan Chase & Co. $ 100,153 March 14, 2019 March 14, 2019 Citibank, N.A. $ 118,546 December 13, 2018 June 7, 2019 Bank of America, N.A. $ 16,589 October 18, 2018 July 1, 2019 Deutsche Bank $ 33,676 December 17, 2018 March 31, 2019 BNP Paribas Corporate & Institutional Banking $ 555 December 14, 2018 August 2, 2019 Morgan Stanley $ 10,781 December 13, 2018 August 23, 2019 Royal Bank of Canada $ 4,454 January 13, 2019 April 16, 2019

Mortgage Loan Participation P_2

Mortgage Loan Participation Purchase and Sale Agreements (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Mortgage Loan Participation Purchase and Sale Agreements	Mortgage loan participation purchase and sale agreements are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average interest rate (1) 3.39 % 2.48 % 3.21 % 2.28 % Average balance $ 78,806 $ 59,701 $ 51,687 $ 65,290 Total interest expense $ 739 $ 409 $ 1,396 $ 1,225 Maximum daily amount outstanding $ 258,983 $ 99,441 $ 258,983 $ 99,441 (1) Excludes the effect of amortization of debt issuance costs of $65,000 and $141,000 for the quarter and nine months ended September 30, 2018, respectively, and $31,000 and $94,000 for the quarter and nine months ended September 30, 2017, respectively. September 30, 2018 December 31, 2017 (dollars in Carrying value: Amount outstanding $ 31,675 $ 44,550 Unamortized debt issuance costs (97 ) (62 ) $ 31,578 $ 44,488 Weighted-average interest rate 3.61 % 2.82 % Mortgage loans acquired for sale pledged to secure mortgage loan participation purchase and sale agreements $ 32,392 $ 47,285

Exchangeable Senior Notes (Tabl

Exchangeable Senior Notes (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Financial Information Relating to Exchangeable Notes	Following is financial information relating to the Exchangeable Notes: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Average balance $ 250,000 $ 250,000 $ 250,000 $ 250,000 Total interest expense $ 3,652 $ 3,636 $ 10,945 $ 10,895 September 30, 2018 December 31, 2017 (in thousands) Carrying value: UPB $ 250,000 $ 250,000 Unamortized debt issuance costs (1,947 ) (2,814 ) $ 248,053 $ 247,186

Notes Payable (Tables)

Notes Payable (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Financial Information Relating to Note Payable	Following is a summary of financial information relating to the notes payable: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars Weighted-average interest rate (1) 4.53 % 6.30 % 4.58 % 5.57 % Average balance $ 445,149 $ 79,345 $ 251,052 $ 152,395 Total interest expense $ 5,351 $ 2,320 $ 9,032 $ 9,719 Maximum daily amount outstanding $ 445,318 $ 160,106 $ 445,318 $ 275,106 (1) Excludes the effect of amortization of debt issuance costs of $255,000 and $426,000 for the quarter and nine months ended September 30, 2018, respectively, and $1.0 million and $3.3 million for the quarter and nine months ended September 30, 2017, respectively. September 30, 2018 December 31, 2017 (dollars in thousands) Carrying value: Amount outstanding $ 450,000 $ — Unamortized debt issuance costs (4,682 ) — $ 445,318 $ — Weighted-average interest rate 4.44 % — MSRs pledged to secure notes payable (1) $ 1,090,406 $ 180,317 (1) During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase Notes payable

Asset-Backed Financing of a V_2

Asset-Backed Financing of a Variable Interest Entity at Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Financial Information Relating to Asset-Backed Financing of a VIE	Following is a summary of financial information relating to the asset-backed financing of a VIE: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (dollars in thousands) Weighted-average fair value $ 285,284 $ 325,763 $ 292,770 $ 337,073 Total interest expense $ 2,740 $ 3,515 $ 7,836 $ 10,520 Weighted-average interest rate 3.52 % 3.34 % 3.51 % 3.41 % September 30, 2018 December 31, 2017 (dollars in thousands) Fair value $ 278,113 $ 307,419 UPB $ 287,086 $ 316,684 Weighted-average interest rate 3.51 % 3.51 %

Liability for Losses Under Re_2

Liability for Losses Under Representations and Warranties (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Company's Liability for Losses under Representations and Warranties	Following is a summary of the Company’s liability for losses under representations and warranties: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Balance, beginning of period $ 7,625 $ 10,697 $ 8,678 $ 15,350 Provision for losses: Pursuant to mortgage loan sales 636 1,075 1,724 2,355 Reduction in liability due to change in estimate (848 ) (1,642 ) (3,030 ) (7,523 ) (Losses incurred) recoveries, net — (83 ) 41 (135 ) Balance, end of period $ 7,413 $ 10,047 $ 7,413 $ 10,047 UPB of mortgage loans subject to representations and warranties at end of period $ 83,370,583 $ 67,196,537

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Company's Outstanding Contractual Commitments	The following table summarizes the Company’s outstanding contractual commitments: September 30, 2018 (in thousands) Commitments to purchase mortgage loans acquired for sale $ 1,682,007 Commitments to fund Deposits securing CRT agreements $ 578,508 Firm commitment to purchase credit risk transfer security $ 294,698 (1) Certain deposits of cash collateral on CRT Agreements are made upon the first to occur of fulfillment of the aggregation obligation or the lapse of the aggregation period.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Preferred Shares of Beneficial Interest	Preferred shares of beneficial interest are summarized below: Series Description (1) Number of shares Liquidation preference Issuance discount Carrying value (in thousands) A 8.125% fixed-to-floating rate cumulative redeemable preferred, issued March 2017 4,600 $ 115,000 $ 3,828 $ 111,172 B 8.00% fixed-to-floating rate cumulative redeemable preferred, issued July 2017 7,800 195,000 6,465 188,535 12,400 $ 310,000 $ 10,293 $ 299,707 (1) Par value is $0.01 per share for both series.
Summary of Share Repurchase Activity	The following table summarizes the Company’s share repurchase activity: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Cumulative total (1) (in thousands) Common shares repurchased — 966 671 1,105 14,731 Cost of common shares repurchased $ — $ 16,417 $ 10,719 $ 18,724 $ 216,625 (1) Amounts represent the share repurchase program total from its inception in August 2015 through September 30, 2018.

Net Mortgage Loan Servicing F_2

Net Mortgage Loan Servicing Fees (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Net Mortgage Loan Servicing Fees	Net mortgage loan servicing fees are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Servicing fees (1) $ 49,864 $ 42,237 $ 147,262 $ 119,223 Ancillary and other fees 3,111 2,043 6,673 4,646 Effect of MSRs: Carried at fair value—change in fair value Realization of cashflows (30,053 ) (2,628 ) (84,689 ) (6,956 ) Other 33,127 (1,349 ) 101,822 (3,414 ) 3,074 (3,977 ) 17,133 (10,370 ) Loss on sale (123 ) — (123 ) — Carried at lower of amortized cost or fair value: Amortization — (21,634 ) — (59,015 ) Additions to impairment valuation allowance — (1,702 ) — (4,287 ) (Losses) gains on hedging derivatives (12,093 ) 4,576 (44,378 ) (1,731 ) (9,142 ) (22,737 ) (27,368 ) (75,403 ) 43,833 21,543 126,567 48,466 From PFSI—MSR recapture income 561 333 1,568 859 Net mortgage loan servicing fees $ 44,394 $ 21,876 $ 128,135 $ 49,325 Average servicing portfolio $ 81,350,980 $ 63,584,416 $ 77,522,709 $ 61,764,228 (1) Includes contractually specified servicing fees, net of Agency guarantee fees.

Net Gain on Mortgage Loans Ac_2

Net Gain on Mortgage Loans Acquired for Sale (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of Net Gain on Mortgage Loans Acquired for Sale	Net gain on mortgage loans acquired for sale is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Cash loss: Mortgage loans $ (104,475 ) $ (51,485 ) $ (272,496 ) $ (135,666 ) Hedging activities 24,659 (13,468 ) 63,047 (16,931 ) (79,816 ) (64,953 ) (209,449 ) (152,597 ) Non cash gain: Recognition of fair value of firm commitment to purchase credit risk transfer security 12,311 — 16,737 — Receipt of MSRs in mortgage loan sale transactions 96,383 82,838 228,337 207,361 Provision for losses relating to representations and warranties provided in mortgage loan sales: Pursuant to mortgage loans sales (636 ) (1,075 ) (1,724 ) (2,355 ) Reduction in liability due to change in estimate 848 1,642 3,030 7,523 212 567 1,306 5,168 Change in fair value of financial instruments held at end of period: IRLCs (3,907 ) 880 (5,733 ) (2,502 ) Mortgage loans 6,013 (1,165 ) 8,389 2,891 Hedging derivatives (9,075 ) (3,475 ) (6,229 ) (15,377 ) (6,969 ) (3,760 ) (3,573 ) (14,988 ) Total from non-affiliates 22,121 14,692 33,358 44,944 From PFSI—cash gain 2,689 3,275 8,221 9,340 $ 24,810 $ 17,967 $ 41,579 $ 54,284

Net Gain (Loss) on Investments

Net Gain (Loss) on Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Investments Debt And Equity Securities [Abstract]
Summary of Net Gain (Loss) on Investments	Net gain (loss) on investments is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) From non-affiliates: Mortgage-backed securities at fair value $ (19,030 ) $ 5,001 $ (50,288 ) $ 9,168 Mortgage loans at fair value: Distressed (3,051 ) 3,277 (17,702 ) 7,523 Held in a VIE (3,630 ) 2,138 (11,992 ) 6,309 CRT Agreements 29,481 15,151 90,528 66,591 Asset-backed financing of a VIE at fair value 3,516 (2,158 ) 12,658 (5,581 ) Hedging derivatives 691 (5,910 ) 1,029 (14,943 ) 7,977 17,499 24,233 69,067 From PFSI—ESS 1,706 (3,665 ) 10,977 (10,920 ) $ 9,683 $ 13,834 $ 35,210 $ 58,147

Net Interest Income (Tables)

Net Interest Income (Tables)	9 Months Ended
	Sep. 30, 2018
Banking And Thrift Interest [Abstract]
Summary of Net Interest Income	Net interest income is summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Interest income: From nonaffiliates: Short-term investments $ 385 $ 132 $ 656 $ 516 Mortgage-backed securities 15,903 7,447 37,127 21,954 Mortgage loans acquired for sale at fair value 22,591 16,202 51,874 40,699 Mortgage loans at fair value: Distressed 5,245 14,213 18,086 53,456 Held in a VIE 3,066 3,766 8,837 11,370 Deposits securing CRT Agreements 3,190 1,440 8,788 2,703 Placement fees relating to custodial funds 7,979 4,330 18,218 8,212 Other 225 49 478 142 58,584 47,579 144,064 139,052 From PFSI—ESS 3,740 3,998 11,584 13,011 62,324 51,577 155,648 152,063 Interest expense: To nonaffiliates: Assets sold under agreements to repurchase (1) 29,725 26,157 79,705 72,280 Mortgage loan participation purchase and sale agreements 739 409 1,396 1,225 Exchangeable Notes 3,652 3,636 10,945 10,895 Notes payable 5,351 2,320 9,032 9,719 Asset-backed financings of a VIE at fair value 2,740 3,515 7,836 10,520 Interest shortfall on repayments of mortgage loans serviced for Agency securitizations 1,897 1,638 5,294 4,068 Interest on mortgage loan impound deposits 693 486 1,596 1,229 44,797 38,161 115,804 109,936 To PFSI—Assets sold under agreement to repurchase 1,812 2,116 5,686 5,946 46,609 40,277 121,490 115,882 Net interest income $ 15,715 $ 11,300 $ 34,158 $ 36,181 (1) In 2017, the Company entered into a master repurchase agreement that provides the Company with incentives to finance mortgage loans approved for satisfying certain consumer relief characteristics as provided in the agreement. During the quarter and nine months ended September 30, 2018, the Company included $5.0 million and $11.0 million, respectively, of such incentives as a reduction of Interest expense

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Share-Based Compensation Activity	The following table summarizes the Company’s share-based compensation activity: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Grants: Restricted share units — 2 129 136 Performance share units — — 116 126 Total share units granted — 2 245 262 Grant date fair value: Restricted share units granted $ — $ 36 $ 2,281 $ 2,317 Performance share units granted — — 1,542 1,675 Total fair value of share units granted $ — $ 36 $ 3,823 $ 3,992 Vestings: Restricted share units 1 — 261 284 Performance share units — — 28 — Total share units vested 1 — 289 284 Forfeitures: Restricted share units 2 — 2 13 Performance share units — — — — Total share units forfeited 2 — 2 13 Compensation expense relating to share-based grants $ 1,566 $ 737 $ 4,322 $ 3,864

Other Expenses (Tables)

Other Expenses (Tables)	9 Months Ended
	Sep. 30, 2018
Other Income And Expenses [Abstract]
Summary of Other Expenses	Other expenses are summarized below: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Common overhead allocation from PFSI $ 1,210 $ 1,193 $ 3,387 $ 4,220 Technology 291 374 1,014 1,088 Insurance 274 300 915 968 Other 1,119 1,434 2,442 4,428 $ 2,894 $ 3,301 $ 7,758 $ 10,704

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Summary of Basic and Diluted Earnings per Share	The following table summarizes the basic and diluted earnings per share calculations: Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands except per share amounts) Net income $ 46,562 $ 19,395 $ 111,173 $ 76,911 Dividends on preferred shares (6,235 ) (6,125 ) (18,703 ) (9,032 ) Effect of participating securities—share-based compensation awards (236 ) (231 ) (541 ) (760 ) Net income attributable to common shareholders $ 40,091 $ 13,039 $ 91,929 $ 67,119 Net income attributable to common shareholders $ 40,091 $ 13,039 $ 91,929 $ 67,119 Interest on Exchangeable Notes, net of income taxes 2,661 — 7,973 6,564 Diluted net income attributable to common shareholders $ 42,752 $ 13,039 $ 99,902 $ 73,683 Weighted-average basic shares outstanding 60,950 66,636 60,880 66,702 Dilutive securities: Shares issuable pursuant to exchange of the Exchangeable Notes 8,467 — 8,467 8,467 Diluted weighted-average number of shares outstanding 69,417 66,636 69,347 75,169 Basic earnings per share $ 0.66 $ 0.20 $ 1.51 $ 1.01 Diluted earnings per share $ 0.62 $ 0.20 $ 1.44 $ 0.98
Summary of Potentially Dilutive Shares Excluded from Computation of Diluted Earnings Per Share	Quarter ended September 30, Nine months ended September 30, 2018 2017 2018 2017 (in thousands) Shares issuable under share-based compensation plan 361 643 403 699 Shares issuable pursuant to exchange of the Exchangeable Notes — 8,467 — —

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Financial Highlights by Operating Segment	Financial highlights by operating segment are summarized below: Quarter ended September 30, 2018 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 5 $ 44,389 $ — $ 44,394 Net gain on mortgage loans acquired for sale 12,496 12,314 — — 24,810 Net gain (loss) on investments — 26,293 (16,610 ) — 9,683 Net interest income (expense): Interest income 22,465 8,675 30,573 611 62,324 Interest expense (12,708 ) (8,792 ) (25,109 ) — (46,609 ) 9,757 (117 ) 5,464 611 15,715 Other income 12,442 1,457 — — 13,899 34,695 39,952 33,243 611 108,501 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 26,256 1,271 8,800 — 36,327 Management fees — — — 6,482 6,482 Other 2,485 5,619 344 5,582 14,030 28,741 6,890 9,144 12,064 56,839 Pre-tax income (loss) $ 5,954 $ 33,062 $ 24,099 $ (11,453 ) $ 51,662 Total assets at end of quarter $ 1,976,188 $ 1,348,750 $ 3,822,572 $ 120,068 $ 7,267,578 Quarter ended September 30, 2017 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 47 $ 21,829 $ — $ 21,876 Net gain on mortgage loans acquired for sale 17,963 4 — — 17,967 Net gain (loss) on investments — 18,562 (4,728 ) — 13,834 Net interest income: Interest income 16,018 15,951 19,426 182 51,577 Interest expense (11,351 ) (13,096 ) (15,830 ) — (40,277 ) 4,667 2,855 3,596 182 11,300 Other income (loss) 11,762 (935 ) — — 10,827 34,392 20,533 20,697 182 75,804 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 23,508 4,273 7,128 — 34,909 Management fees — — — 6,038 6,038 Other 2,574 3,194 265 4,658 10,691 26,082 7,467 7,393 10,696 51,638 Pre-tax income (loss) $ 8,310 $ 13,066 $ 13,304 $ (10,514 ) $ 24,166 Total assets at end of quarter $ 1,304,647 $ 1,959,792 $ 2,414,477 $ 106,127 $ 5,785,043 Nine months ended September 30, 2018 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 29 $ 128,106 $ — $ 128,135 Net gain on mortgage loans acquired for sale 24,810 16,769 — — 41,579 Net gain (loss) on investments — 72,744 (37,534 ) — 35,210 Net interest income (expense): Interest income 51,456 27,634 75,423 1,135 155,648 Interest expense (30,039 ) (28,899 ) (62,552 ) — (121,490 ) 21,417 (1,265 ) 12,871 1,135 34,158 Other income (loss) 28,410 (351 ) — 24 28,083 74,637 87,926 103,443 1,159 267,165 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 52,759 5,529 24,992 — 83,280 Management fees — — — 17,906 17,906 Other 4,778 13,077 166 16,172 34,193 57,537 18,606 25,158 34,078 135,379 Pre-tax income (loss) $ 17,100 $ 69,320 $ 78,285 $ (32,919 ) $ 131,786 Total assets at end of period $ 1,976,188 $ 1,348,750 $ 3,822,572 $ 120,068 $ 7,267,578 Nine months ended September 30, 2017 Correspondent production Credit sensitive strategies Interest rate sensitive strategies Corporate Total (in thousands) Net investment income: Net mortgage loan servicing fees $ — $ 91 $ 49,234 $ — $ 49,325 Net gain on mortgage loans acquired for sale 54,117 167 — — 54,284 Net gain (loss) on investments — 74,695 (16,548 ) — 58,147 Net interest income: Interest income 40,194 57,011 54,200 658 152,063 Interest expense (28,214 ) (41,178 ) (46,490 ) — (115,882 ) 11,980 15,833 7,710 658 36,181 Other income (loss) 30,576 (4,281 ) — 5 26,300 96,673 86,505 40,396 663 224,237 Expenses: Mortgage loan fulfillment and servicing fees payable to PFSI 61,191 12,143 19,837 — 93,171 Management fees — — — 16,684 16,684 Other 6,614 11,419 1,094 16,656 35,783 67,805 23,562 20,931 33,340 145,638 Pre-tax income (loss) $ 28,868 $ 62,943 $ 19,465 $ (32,677 ) $ 78,599 Total assets at end of period $ 1,304,647 $ 1,959,792 $ 2,414,477 $ 106,127 $ 5,785,043

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Summary of Supplemental Cash Flow Information	Nine months ended September 30, 2018 2017 (in thousands) Income tax payments, net of refunds $ 900 $ (294 ) Interest payments $ 124,332 $ 115,108 Cumulative effect on accumulated deficit of conversion to fair value accounting $ 14,361 $ — Non-cash investing activities: Transfer of mortgage loans and advances to real estate acquired in settlement of loans $ 26,229 $ 76,981 Transfer of real estate acquired in settlement of mortgage loans to real estate held for investment $ 4,123 $ 14,300 Transfer of real estate acquired in settlement of mortgage loans from real estate held for investment $ 1,112 $ — Receipt of mortgage servicing rights as proceeds from sales of mortgage loans $ 228,337 $ 207,361 Receipt of excess servicing spread pursuant to recapture agreement with PennyMac Financial Services, Inc. $ 1,983 $ 4,160 Capitalization of servicing advances pursuant to mortgage loan modifications $ 4,734 $ 17,759 Non-cash financing activities: Recognition of financing premium arising from repurchase agreement derivatives $ 11,411 $ — Dividends declared, not paid $ 28,817 $ 31,655

Regulatory Capital and Liquid_2

Regulatory Capital and Liquidity Requirements (Tables)	9 Months Ended
	Sep. 30, 2018
Mortgage Banking [Abstract]
Summary of Capital and Liquidity Amounts and Requirements by Agencies	Such Agencies’ capital and liquidity amounts and requirements, the calculations of which are defined by each entity, are summarized below: Net Worth (1) Tangible Net Worth / Total Assets Ratio (1) Liquidity (1) Fannie Mae and Freddie Mac Actual Required Actual Required Actual Required (in thousands) (in thousands) September 30, 2018 $ 555,214 $ 213,379 11 % 6 % $ 100,478 $ 28,983 December 31, 2017 $ 487,535 $ 182,818 12 % 6 % $ 73,252 $ 25,245 (1) Calculated in accordance with the Agencies’ requirements.

Organization - Additional Infor

Organization - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018Segment
Accounting Policies [Abstract]
Number of business segments	4
Percentage of taxable income for distributions	90.00%

Accounting Developments - Addit

Accounting Developments - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Jan. 01, 2018	Sep. 30, 2017
Accounting Developments [Line Items]
Restricted cash	$ 0		$ 0
Accounting Standards Update 2014-11 Transfers and Servicing [Member]
Accounting Developments [Line Items]
Change in accounting principle, increase in income taxes payable		$ 5,300,000
Change in accounting principle, increase in shareholders equity		14,400,000
Accounting Standards Update 2016-18 [Member]
Accounting Developments [Line Items]
Restricted cash	0
Restricted cash equivalents	$ 0
MSRs [Member] | Accounting Standards Update 2014-11 Transfers and Servicing [Member]
Accounting Developments [Line Items]
Change in accounting principle, increase in investment		$ 19,700,000

Concentration of Risks - Summar

Concentration of Risks - Summary of Holdings of Assets Purchased (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Investment portfolio purchases through one or more subsidiaries of Citigroup Inc. and JPMorgan Chase & Co. as of:
Investment portfolio purchases above through one or more subsidiaries total	$ 400,929	$ 860,860
Total carrying value of distressed mortgage loans at fair value and REO	436,599	931,298
Assets Purchased From JPMorgan Chase & Co [Member]
Investment portfolio purchases through one or more subsidiaries of Citigroup Inc. and JPMorgan Chase & Co. as of:
Investment portfolio purchases above through one or more subsidiaries Mortgage loans at fair value	135,486	315,437
Investment portfolio purchases above through one or more subsidiaries REO	42,003	66,294
Investment portfolio purchases above through one or more subsidiaries total	177,489	381,731
Assets Purchased from Citigroup [Member]
Investment portfolio purchases through one or more subsidiaries of Citigroup Inc. and JPMorgan Chase & Co. as of:
Investment portfolio purchases above through one or more subsidiaries Mortgage loans at fair value	133,547	280,488
Investment portfolio purchases above through one or more subsidiaries REO	13,223	26,702
Investment portfolio purchases above through one or more subsidiaries total	146,770	307,190
Assets Purchased from Bank of America Corporation [Member]
Investment portfolio purchases through one or more subsidiaries of Citigroup Inc. and JPMorgan Chase & Co. as of:
Investment portfolio purchases above through one or more subsidiaries Mortgage loans at fair value	60,884	143,969
Investment portfolio purchases above through one or more subsidiaries REO	15,786	27,970
Investment portfolio purchases above through one or more subsidiaries total	$ 76,670	$ 171,939

Transactions with Related Par_3

Transactions with Related Parties - Correspondent Production Activities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018USD ($)
Mortgage Loans On Real Estate [Line Items]
Servicing agreement expiration date	Sep. 12, 2020
Renewal period of servicing agreement	18 months
Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Interest income and sourcing fee	0.035%
Minimum [Member]
Mortgage Loans On Real Estate [Line Items]
Interest income and sourcing fee	0.02%
Penny Mac Loan Services Llc | Fannie Mae Or Freddie Mac Mortgage Loans | Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Basis point for monthly fulfillment fee	0.35%
Penny Mac Loan Services Llc | Mortgage Loans Sold And Securitized | Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Basis point for monthly fulfillment fee	0.50%
Mortgage banking services [Member]
Mortgage Loans On Real Estate [Line Items]
Mortgage loan fees per annum	$ 1,500
Mortgage loan fees per loan	$ 35
Servicing agreement expiration date	Sep. 12, 2020
Renewal period of servicing agreement	18 months
Warehouse services [Member]
Mortgage Loans On Real Estate [Line Items]
Servicing agreement expiration date	Sep. 12, 2020
Renewal period of servicing agreement	18 months

Transactions with Related Par_4

Transactions with Related Parties - Summary of Correspondent Production Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Mortgage loans fulfillment fees earned by PLS	$ 26,256	$ 23,507	$ 52,759	$ 61,184
Purchases of mortgage loans acquired for sale from PLS			2,336,162	373,108
Mortgage loans included in Mortgage loans acquired for sale at fair value pending sale to PLS	1,949,432		1,949,432		$ 1,269,515
PennyMac Loan Services, LLC [Member]
Related Party Transaction [Line Items]
Mortgage loans fulfillment fees earned by PLS	26,256	23,507	52,759	61,184
Unpaid principal balance ("UPB") of mortgage loans fulfilled by PLS	7,517,883	6,530,036	17,139,884	17,079,969
Sourcing fees received from PLS included in Net gain on mortgage loans acquired for sale	2,689	3,275	8,221	9,340
UPB of mortgage loans sold to PLS	8,916,654	10,915,194	27,404,022	31,131,154
Early purchase program fees paid to PLS included in Mortgage loan servicing fees	0	1	0	7
Purchases of mortgage loans acquired for sale from PLS	908,525	332,886	2,336,162	373,108
Tax service fee paid to PLS included in Other expense	2,119	$ 2,108	4,869	$ 5,377
Mortgage loans included in Mortgage loans acquired for sale at fair value pending sale to PLS	$ 217,334		$ 217,334		$ 279,571

Transactions with Related Par_5

Transactions with Related Parties - Mortgage Loan Servicing Activities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018USD ($)
Mortgage Loans On Real Estate [Line Items]
Servicing agreement expiration date	Sep. 12, 2020
Renewal period of servicing agreement	18 months
Penny Mac Loan Services Llc
Mortgage Loans On Real Estate [Line Items]
REO rental fee	$ 30
Lease renewal fee for REO	$ 100
Rental income percentage gross	9.00%
Penny Mac Loan Services Llc | Distressed mortgage loans [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees for REO per month	$ 75
Activity based fees	$ 500
Services agreement fees collection period	18 months
Penny Mac Loan Services Llc | Distressed mortgage loans [Member] | Minimum [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees per month	$ 30
Activity based fees	750
Penny Mac Loan Services Llc | Distressed mortgage loans [Member] | Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees per month	100
Activity based fees	1,750
Penny Mac Loan Services Llc | Whole loans [Member]
Mortgage Loans On Real Estate [Line Items]
Supplemental fee received per month	25
Penny Mac Loan Services Llc | Subserviced loan [Member] | Fixed-Rate Mortgage Loans [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees per month	7.50
Penny Mac Loan Services Llc | Subserviced loan [Member] | Adjustable rate mortgage loans [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees per month	8.50
Penny Mac Loan Services Llc | Non-Distressed Mortgage Loans [Member]
Mortgage Loans On Real Estate [Line Items]
Base servicing fees for REO per month	75
Penny Mac Loan Services Llc | Non-Distressed Mortgage Loans [Member] | Minimum [Member]
Mortgage Loans On Real Estate [Line Items]
Additional servicing fees per loan per month	10
Penny Mac Loan Services Llc | Non-Distressed Mortgage Loans [Member] | Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Additional servicing fees per loan per month	$ 55
PennyMac Financial Services, Inc. [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of cash in amount equal to fair market value of MSRs related to all loans	30.00%

Transactions with Related Par_6

Transactions with Related Parties - Summary of Mortgage Loan Servicing Fees Earned and Mortgage Servicing Rights Recaptured Income Earned (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Mortgage loan servicing fees	$ 10,071	$ 11,402	$ 30,521	$ 31,987
Average MSR portfolio	81,350,980	63,584,416	77,522,709	61,764,228
PennyMac Loan Services, LLC [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	35	54	103	96
Average MSR portfolio	81,350,980	63,584,416	77,522,709	61,764,228
MSR recapture income recognized included in Net mortgage loan servicing fees ‒ from PennyMac Financial Services, Inc.	561	333	1,568	859
PennyMac Loan Services, LLC [Member] | Mortgage loans acquired for sale at fair value [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	316	276	739	742
Average MSR portfolio	1,833,232	1,460,054	1,460,547	1,271,158
PennyMac Loan Services, LLC [Member] | Distressed mortgage loans [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	1,271	4,273	5,528	12,143
Average MSR portfolio	417,487	1,104,738	537,300	1,210,328
PennyMac Loan Services, LLC [Member] | Mortgage servicing rights [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	8,449	6,799	24,151	19,006
PennyMac Loan Services, LLC [Member] | Mortgage loans held in VIE [Member]
Related Party Transaction [Line Items]
Average MSR portfolio	299,415	339,464	306,856	350,607
PennyMac Loan Services, LLC [Member] | Base [Member] | Mortgage loans acquired for sale at fair value [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	98	88	250	235
PennyMac Loan Services, LLC [Member] | Base [Member] | Distressed mortgage loans [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	614	1,571	2,328	5,284
PennyMac Loan Services, LLC [Member] | Base [Member] | Mortgage servicing rights [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	8,291	6,648	23,772	18,631
PennyMac Loan Services, LLC [Member] | Base [Member] | Mortgage loans held in VIE [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	10,071	11,402	30,521	31,987
PennyMac Loan Services, LLC [Member] | Activity-based [Member] | Mortgage loans acquired for sale at fair value [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	218	188	489	507
PennyMac Loan Services, LLC [Member] | Activity-based [Member] | Distressed mortgage loans [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	657	2,702	3,200	6,859
PennyMac Loan Services, LLC [Member] | Activity-based [Member] | Mortgage servicing rights [Member]
Related Party Transaction [Line Items]
Mortgage loan servicing fees	$ 158	$ 151	$ 379	$ 375

Transactions with Related Par_7

Transactions with Related Parties - Management Fees - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2018	Aug. 04, 2009
Mortgage Loans On Real Estate [Line Items]
Servicing agreement expiration date	Sep. 12, 2020
Termination fees, description	The termination fee is equal to three times the sum of (a) the average annual base management fee, and (b) the average annual performance incentive fee earned by PCM, in each case during the 24-month period immediately preceding the date of termination.
Fannie Mae [Member]
Mortgage Loans On Real Estate [Line Items]
MBS yield, average number of year	30 years
PNMAC Capital Management LLC [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of change in net income due to quarterly adjustments	8.00%
Servicing agreement expiration date	Sep. 12, 2020
Services agreement fees collection period	18 months
Termination fees, description	The termination fee is equal to three times the sum of (a) the average annual base management fee, and (b) the average annual performance incentive fee earned by PCM, in each case during the 24-month period before termination.
PMT agreed to reimburse PCM for a payment	$ 120,000
PNMAC Capital Management LLC [Member] | 1.5% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee annual rate	1.50%
PNMAC Capital Management LLC [Member] | 1.375% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee annual rate	1.375%
PNMAC Capital Management LLC [Member] | 1.25% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee annual rate	1.25%
PNMAC Capital Management LLC [Member] | Net income exceeds 10% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of net income for calculation of performance incentive fees	10.00%
Percentage of return on equity	12.00%
PNMAC Capital Management LLC [Member] | Net income exceeds 15% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of net income for calculation of performance incentive fees	15.00%
Percentage of return on equity	16.00%
PNMAC Capital Management LLC [Member] | Net income exceeds 20% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of net income for calculation of performance incentive fees	20.00%
PNMAC Capital Management LLC [Member] | Maximum [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of performance incentive fee paid in Company's common shares	50.00%
PMT agreed to reimburse PCM for a payment		$ 2,900,000
PNMAC Capital Management LLC [Member] | Maximum [Member] | 1.5% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee shareholders' equity limit	$ 2,000,000,000
PNMAC Capital Management LLC [Member] | Maximum [Member] | 1.375% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee shareholders' equity limit	$ 5,000,000,000
PNMAC Capital Management LLC [Member] | Maximum [Member] | Net income exceeds 10% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of return on equity	8.00%
PNMAC Capital Management LLC [Member] | Maximum [Member] | Net income exceeds 15% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of return on equity	12.00%
PNMAC Capital Management LLC [Member] | Maximum [Member] | Net income exceeds 20% [Member]
Mortgage Loans On Real Estate [Line Items]
Percentage of return on equity	16.00%
PNMAC Capital Management LLC [Member] | Minimum [Member] | 1.375% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee shareholders' equity limit	$ 2,000,000,000
PNMAC Capital Management LLC [Member] | Minimum [Member] | 1.25% per annum of stockholders equity [Member]
Mortgage Loans On Real Estate [Line Items]
Base management fee shareholders' equity limit	$ 5,000,000,000
PennyMac Financial Services, Inc. [Member]
Mortgage Loans On Real Estate [Line Items]
Performance incentive fee description	The performance incentive fee is equal to the sum of: (a) 10% of the amount by which “net income” for the quarter exceeds (i) an 8% return on equity plus the high watermark, up to (ii) a 12% return on equity; plus (b) 15% of the amount by which “net income” for the quarter exceeds (i) a 12% return on equity plus the high watermark, up to (ii) a 16% return on equity; plus (c) 20% of the amount by which “net income” for the quarter exceeds a 16% return on equity plus the high watermark.

Transactions with Related Par_8

Transactions with Related Parties - Summary of Base Management and Performance Incentive Fees Payable (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Total management fee incurred during the period	$ 6,482	$ 6,038	$ 17,906	$ 16,684
PNMAC Capital Management LLC [Member]
Related Party Transaction [Line Items]
Total management fee incurred during the period	6,482	6,038	17,906	16,684
PNMAC Capital Management LLC [Member] | Base [Member]
Related Party Transaction [Line Items]
Total management fee incurred during the period	5,799	6,038	17,223	16,380
PNMAC Capital Management LLC [Member] | Performance incentive [Member]
Related Party Transaction [Line Items]
Total management fee incurred during the period	$ 683	$ 0	$ 683	$ 304

Transactions with Related Par_9

Transactions with Related Parties - Summary of Expenses (Detail) - PNMAC Capital Management LLC [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Common overhead incurred by PCM and its affiliates	$ 1,210	$ 1,193	$ 3,387	$ 4,220
Compensation	120	0	360	0
Expenses incurred on the Company’s behalf, net	527	196	586	849
Total expenses incurred in transaction with affiliates	1,857	1,389	4,333	5,069
Payments and settlements during the period	$ 21,650	$ 22,786	$ 45,265	$ 63,249

Transactions with Related Pa_10

Transactions with Related Parties - Note Payable to PLS - Additional Information (Detail) - USD ($)	Dec. 19, 2016	Aug. 04, 2009	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Recapture percentage loan fee rate and unpaid principal balance refinance mortgage loans	90.00%
Recapture percentage loan fee rate and unpaid principal balance modified mortgage loans	90.00%
Payments of contingent underwriting fees to underwriters			$ 0	$ 61,000	$ 0	$ 61,000
Performance incentive fees incurred			$ 683,000		$ 683,000
VFN [Member]
Related Party Transaction [Line Items]
Maximum principal balance	$ 1,000,000,000
PennyMac Financial Services, Inc. [Member]
Related Party Transaction [Line Items]
Number of common shares held by affiliate			75,000		75,000			75,000
PNMAC Capital Management LLC [Member]
Related Party Transaction [Line Items]
PMT agreed to reimburse PCM for a payment			$ 120,000		$ 120,000
Payment of contingent underwriting fees			$ 0		$ 0
Reimbursement of contingent underwriting fee				$ 30,000		$ 30,000
PNMAC Capital Management LLC [Member] | Scenario Forecast [Member]
Related Party Transaction [Line Items]
PMT agreed to reimburse PCM for a payment							$ 68,000
Maximum [Member]
Related Party Transaction [Line Items]
Aggregate ESS transferred	$ 200,000
Maximum [Member] | PNMAC Capital Management LLC [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

Transactions with Related Pa_11

Transactions with Related Parties - Summary of Investing Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
ESS:
Interest income	$ 62,324	$ 51,577	$ 155,648	$ 152,063
Net gain (loss) included in Net gain (loss) on investments:
Net (loss) gain on investments	9,683	13,834	35,210	58,147
Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value	223,275		223,275		$ 236,534
PennyMac Financial Services, Inc. [Member]
ESS:
Received pursuant to a recapture agreement	499	1,207	1,983	4,160
Repayments	11,543	13,410	35,852	42,320
Interest income	3,740	3,998	11,584	13,011
Net gain (loss) included in Net gain (loss) on investments:
Valuation changes	1,109	(4,828)	9,026	(14,757)
Recapture income	597	1,163	1,951	3,837
Net (loss) gain on investments	1,706	$ (3,665)	10,977	$ (10,920)
Excess servicing spread purchased from PennyMac Financial Services, Inc. at fair value	$ 223,275		$ 223,275		$ 236,534

Transactions with Related Pa_12

Transactions with Related Parties - Summary of Financing Activities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Interest expense	$ 46,609	$ 40,277	$ 121,490	$ 115,882
PennyMac Financial Services, Inc. [Member]
Related Party Transaction [Line Items]
Interest expense	1,812	2,116	5,686	5,946
Assets sold to PFSI under agreement to repurchase	133,128		133,128		$ 144,128
Conditional Reimbursement payable to PFSI included in Accounts payable and accrued liabilities	870		870		870
PennyMac Financial Services, Inc. [Member] | Accounts Payable and Accrued Liabilities [Member]
Related Party Transaction [Line Items]
Conditional Reimbursement payable to PFSI included in Accounts payable and accrued liabilities	870		870		$ 870
PNMAC Capital Management LLC [Member]
Related Party Transaction [Line Items]
Conditional Reimbursements paid to PCM	$ 0	$ 30	$ 0	$ 30

Transactions with Related Pa_13

Transactions with Related Parties - Summary of Amounts Receivable From and Payable to PFSI (Detail) - PennyMac Financial Services, Inc. [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Due from PFSI:
MSR recapture receivable	$ 250	$ 282
Other	2,101	3,872
Due from Affiliates	2,351	4,154
Due to PFSI:
Fulfillment fees	12,078	346
Management fees	6,482	5,901
Mortgage loan servicing fees	3,765	6,583
Allocated expenses and expenses paid by PFSI on PMT’s behalf	2,295	11,542
Correspondent production fees	1,864	1,735
Conditional Reimbursement	870	870
Interest on Assets sold to PFSI under agreement to repurchase	113	142
Total expense due to affiliate	$ 27,467	$ 27,119

Loan Sales and Variable Inter_3

Loan Sales and Variable Interest Entities - Summary of Cash Flows between Company and Transferees in Transfers Accounted for Sales (Detail) - Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Cash flows:
Proceeds from sales	$ 8,435,791	$ 7,035,994	$ 18,992,722	$ 17,683,444
Mortgage loan servicing fees received	$ 49,864	$ 42,237	$ 147,262	$ 119,223

Loan Sales and Variable Inter_4

Loan Sales and Variable Interest Entities - Summary of Collection Status Information for Mortgage Loans Accounted for Sales (Detail) - Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Mortgage Loans On Real Estate [Line Items]
UPB of mortgage loans outstanding	$ 83,913,215	$ 71,639,351
UPB of delinquent mortgage loans:
30-89 days delinquent	601,114	532,673
90 or more days delinquent:
Not in foreclosure	140,122	280,786
In foreclosure	36,069	25,258
UPB of mortgage loans in bankruptcy	66,377	52,202
Custodial funds managed by the Company	$ 1,203,229	$ 879,321

Loan Sales and Variable Inter_5

Loan Sales and Variable Interest Entities - Summary of Credit Risk Transfer Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Carrying value of CRT Agreements:
Deposits securing CRT agreements	$ 662,624		$ 662,624		$ 588,867
Interest-only security payable at fair value	8,821		8,821		7,070
CRT Agreement assets pledged to secure Assets sold under agreements to repurchase:
Deposits securing CRT Agreements	378,090		378,090		400,778
Derivative assets	27,710		27,710		26,058
Commitments to fund Deposits securing credit risk transfer agreements	578,508		578,508
Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] | Credit Risk Transfer Agreements [Member]
Transfer Of Financial Assets Accounted For As Sales [Line Items]
UPB of mortgage loans sold under CRT Agreements	0	$ 4,126,946	5,546,977	$ 9,722,067
Deposits securing CRT Agreements	18,558	44,998	96,446	102,146
(Decrease) increase in commitments to fund Deposits securing CRT Agreements resulting from sale of mortgage loans under CRT Agreements	(18,558)	108,051	96,037	264,165
Interest earned on Deposits securing CRT Agreements	3,190	1,440	8,788	2,703
Gains recognized on CRT Agreements included in Net gain (loss) on investments
Realized	23,367	10,798	64,907	27,595
Resulting from valuation changes	7,185	4,162	27,714	41,268
Gains (losses) recognized on gross derivative related to credit risk transactions	30,552	14,960	92,621	68,863
Change in fair value of Interest-only security payable at fair value	(3,083)	191	(4,105)	(2,272)
Gains (losses) recognized on net derivative related to credit risk transactions	27,469	15,151	88,516	66,591
Payments made to settle losses	443	$ 539	1,452	$ 950
UPB of mortgage loans subject to credit guarantee obligations	30,648,306		30,648,306		26,845,392
Collection status (in UPB):
Current	30,342,833		30,342,833		26,540,953
30—89 days delinquent	226,447		226,447		179,144
90—180 days delinquent	32,852		32,852		101,114
180 or more days delinquent	15,520		15,520		5,146
Foreclosure	9,339		9,339		5,463
Bankruptcy	21,315		21,315		13,572
Carrying value of CRT Agreements:
Deposits securing CRT agreements	662,624		662,624		588,867
Interest-only security payable at fair value	8,821		8,821		7,070
CRT Agreement assets pledged to secure Assets sold under agreements to repurchase:
Deposits securing CRT Agreements	378,090		378,090		400,778
Commitments to fund Deposits securing credit risk transfer agreements	578,508		578,508		482,471
Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] | Credit Risk Transfer Agreements [Member] | Derivative Assets [Member]
Carrying value of CRT Agreements:
Derivative assets	126,354		126,354		98,640
CRT Agreement assets pledged to secure Assets sold under agreements to repurchase:
Derivative assets	$ 27,710		$ 27,710		$ 26,058

Loan Sales and Variable Inter_6

Loan Sales and Variable Interest Entities - Summary of Activity Under Purchase Commitments (Detail) - Credit Risk Transfer Agreements [Member] - Purchase Commitment [Member] $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)
Transfer Of Financial Assets Accounted For As Sales [Line Items]
UPB of mortgage loans sold	$ 6,773,336	$ 8,308,708
Fair value of firm commitment recognized in Gain on sale of mortgage loans	12,311	16,737
Gains recognized on CRT Agreements included in Net gain (loss) on investments	2,012	2,012
Increase in face amount of firm commitment to purchase securities backed by mortgage loans sold	236,875	294,698
Firm commitment to purchase CRT securities	294,698	294,698
Fair value of firm commitment	18,749	18,749
UPB of mortgage loans sold subject to firm commitment to purchase securities related to such loans	8,097,660	8,097,660
Collection status (in UPB):
Current	8,073,018	8,073,018
30—89 days delinquent	24,439	24,439
90—180 days delinquent	203	203
180 or more days delinquent	0	0
Foreclosure	0	0
Bankruptcy	$ 0	$ 0

Loan Sales and Variable Inter_7

Loan Sales and Variable Interest Entities - Additional Information (Detail) - Jumbo Mortgage Loan Financing [Member] - Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] - USD ($) $ in Millions	Sep. 30, 2013	Sep. 30, 2018	Dec. 31, 2017
Mortgage Loans on Real Estate [Line Items]
Certificates issued	$ 537
Weighted yield	3.90%
Fair value of certificates retained		$ 14.1	$ 9.7

Fair Value - Additional Informa

Fair Value - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Mortgage Servicing Rights [Line Items]
Mortgage loans description	Note interest rate pools of 50 basis points
Basis point for mortgage loan	0.50%
Fair value of exchangeable senior notes	$ 248.7	$ 244.9
Repurchase Agreement Derivatives [Member] | Level 3 [Member]
Mortgage Servicing Rights [Line Items]
Ratio included in estimated fair value	97.00%	97.00%
Maximum [Member]
Mortgage Servicing Rights [Line Items]
Fixed-rate mortgage loans	4.50%
Minimum [Member]
Mortgage Servicing Rights [Line Items]
Fixed-rate mortgage loans	3.00%
MSRs Backed by Mortgage Loans [Member]
Mortgage Servicing Rights [Line Items]
Initial interest rates	less than or equal to 4.5%
MSRs Backed by Mortgage Loans [Member] | Maximum [Member]
Mortgage Servicing Rights [Line Items]
Interest rate	4.50%

Fair Value - Summary of Financi

Fair Value - Summary of Financial Statement Items Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Assets:
Short-term investments	$ 26,736		$ 18,398
Mortgage-backed securities at fair value	2,126,507		989,461
Mortgage loans acquired for sale at fair value	1,949,432		1,269,515
Excess servicing spread purchased from PFSI	223,275		236,534
Derivative assets:
Derivative assets	161,535		115,803
Derivative assets, Netting	(17,958)		(1,922)
Total derivative assets after netting	143,577		113,881
Firm commitment to purchase credit risk transfer security at fair value	18,749		0
Mortgage servicing rights at fair value	1,109,741	$ 1,010,507	91,459	$ 82,312	$ 77,624	$ 64,136
Liabilities:
Asset-backed financing of a VIE at fair value	278,113		307,419
Interest-only security payable at fair value	8,821		7,070
Derivative liabilities:
Derivative liabilities	17,101		3,305
Derivative liabilities, Netting	(5,221)		(1,999)
Total derivative liabilities after netting	11,880		1,306
CRT Agreements [Member]
Derivative assets:
Derivative assets	126,354		98,640
Derivative assets, Netting	0		0
Total derivative assets after netting	126,354		98,640
Derivative liabilities:
Derivative liabilities	0		0
Interest Rate Lock Commitments [Member]
Derivative assets:
Derivative assets	2,317		4,859
Total derivative assets after netting	2,317		4,859
Derivative liabilities:
Derivative liabilities	3,418		227
Forward Purchase Contracts [Member]
Derivative assets:
Derivative assets	1,761		4,343
Derivative assets, Netting	0		0
Total derivative assets after netting	1,761		4,343
Derivative liabilities:
Derivative liabilities	11,964		248
Forward Sales Contracts [Member]
Derivative assets:
Derivative assets	19,238		387
Derivative assets, Netting	0		0
Total derivative assets after netting	19,238		387
Derivative liabilities:
Derivative liabilities	1,719		2,830
MBS Put Options [Member]
Derivative assets:
Derivative assets	2,302		3,170
Derivative assets, Netting	0		0
Total derivative assets after netting	2,302		3,170
Derivative liabilities:
Derivative liabilities	0		0
MBS Call Options [Member]
Derivative assets:
Derivative assets	7		0
Derivative assets, Netting	0		0
Total derivative assets after netting	7		0
Derivative liabilities:
Derivative liabilities	0		0
Put Options on Interest Rate Futures [Member]
Derivative assets:
Derivative assets	141		656
Derivative assets, Netting	0		0
Total derivative assets after netting	141		656
Derivative liabilities:
Derivative liabilities	0		0
Repurchase Agreement Derivatives [Member]
Derivative assets:
Derivative assets	9,415		3,748
Derivative assets, Netting	0		0
Total derivative assets after netting	9,415		3,748
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member]
Assets:
Short-term investments	26,736		18,398
Mortgage-backed securities at fair value	2,126,507		989,461
Mortgage loans acquired for sale at fair value	1,949,432		1,269,515
Mortgage loans at fair value	633,168		1,089,473
Excess servicing spread purchased from PFSI	223,275		236,534
Derivative assets:
Derivative assets	161,535		115,803
Derivative assets, Netting	(17,958)		(1,922)
Total derivative assets after netting	143,577		113,881
Firm commitment to purchase credit risk transfer security at fair value	18,749
Mortgage servicing rights at fair value	1,109,741		91,459
Total Assets	6,231,185		3,808,721
Liabilities:
Asset-backed financing of a VIE at fair value	278,113		307,419
Interest-only security payable at fair value	8,821		7,070
Derivative liabilities:
Derivative liabilities	17,101		3,305
Derivative liabilities, Netting	(5,221)		(1,999)
Total derivative liabilities after netting	11,880		1,306
Total liabilities	298,814		315,795
Recurring [Member] | CRT Agreements [Member]
Derivative assets:
Derivative assets	126,354		98,640
Recurring [Member] | Interest Rate Lock Commitments [Member]
Derivative assets:
Derivative assets	2,317		4,859
Derivative liabilities:
Derivative liabilities	3,418		227
Recurring [Member] | Forward Purchase Contracts [Member]
Derivative assets:
Derivative assets	1,761		4,343
Derivative liabilities:
Derivative liabilities	11,964		248
Recurring [Member] | Forward Sales Contracts [Member]
Derivative assets:
Derivative assets	19,238		387
Derivative liabilities:
Derivative liabilities	1,719		2,830
Recurring [Member] | Level 1 [Member]
Assets:
Short-term investments	26,736		18,398
Mortgage-backed securities at fair value	0		0
Mortgage loans acquired for sale at fair value	0		0
Mortgage loans at fair value	0		0
Excess servicing spread purchased from PFSI	0		0
Derivative assets:
Derivative assets	141		656
Derivative assets, Netting	0		0
Total derivative assets after netting	141		656
Firm commitment to purchase credit risk transfer security at fair value	0
Mortgage servicing rights at fair value	0		0
Total Assets	26,877		19,054
Liabilities:
Asset-backed financing of a VIE at fair value	0		0
Interest-only security payable at fair value	0		0
Derivative liabilities:
Derivative liabilities	0		0
Derivative liabilities, Netting	0		0
Total derivative liabilities after netting	0		0
Total liabilities	0		0
Recurring [Member] | Level 1 [Member] | CRT Agreements [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Level 1 [Member] | Interest Rate Lock Commitments [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | Level 1 [Member] | Forward Purchase Contracts [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | Level 1 [Member] | Forward Sales Contracts [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | Level 2 [Member]
Assets:
Short-term investments	0		0
Mortgage-backed securities at fair value	2,126,507		989,461
Mortgage loans acquired for sale at fair value	1,942,335		1,261,380
Mortgage loans at fair value	292,174		321,040
Excess servicing spread purchased from PFSI	0		0
Derivative assets:
Derivative assets	23,308		7,900
Derivative assets, Netting	0		0
Total derivative assets after netting	23,308		7,900
Firm commitment to purchase credit risk transfer security at fair value	0
Mortgage servicing rights at fair value	0		0
Total Assets	4,384,324		2,579,781
Liabilities:
Asset-backed financing of a VIE at fair value	278,113		307,419
Interest-only security payable at fair value	0		0
Derivative liabilities:
Derivative liabilities	13,683		3,078
Derivative liabilities, Netting	0		0
Total derivative liabilities after netting	13,683		3,078
Total liabilities	291,796		310,497
Recurring [Member] | Level 2 [Member] | CRT Agreements [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Level 2 [Member] | Interest Rate Lock Commitments [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | Level 2 [Member] | Forward Purchase Contracts [Member]
Derivative assets:
Derivative assets	1,761		4,343
Derivative liabilities:
Derivative liabilities	11,964		248
Recurring [Member] | Level 2 [Member] | Forward Sales Contracts [Member]
Derivative assets:
Derivative assets	19,238		387
Derivative liabilities:
Derivative liabilities	1,719		2,830
Recurring [Member] | Level 3 [Member]
Assets:
Short-term investments	0		0
Mortgage-backed securities at fair value	0		0
Mortgage loans acquired for sale at fair value	7,097		8,135
Mortgage loans at fair value	340,994		768,433
Excess servicing spread purchased from PFSI	223,275		236,534
Derivative assets:
Derivative assets	138,086		107,247
Derivative assets, Netting	0		0
Total derivative assets after netting	138,086		107,247
Firm commitment to purchase credit risk transfer security at fair value	18,749
Mortgage servicing rights at fair value	1,109,741		91,459
Total Assets	1,837,942		1,211,808
Liabilities:
Asset-backed financing of a VIE at fair value	0		0
Interest-only security payable at fair value	8,821		7,070
Derivative liabilities:
Derivative liabilities	3,418		227
Derivative liabilities, Netting	0		0
Total derivative liabilities after netting	3,418		227
Total liabilities	12,239		7,297
Recurring [Member] | Level 3 [Member] | CRT Agreements [Member]
Derivative assets:
Derivative assets	126,354		98,640
Recurring [Member] | Level 3 [Member] | Interest Rate Lock Commitments [Member]
Derivative assets:
Derivative assets	2,317		4,859
Derivative liabilities:
Derivative liabilities	3,418		227
Recurring [Member] | Level 3 [Member] | Forward Purchase Contracts [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | Level 3 [Member] | Forward Sales Contracts [Member]
Derivative assets:
Derivative assets	0		0
Derivative liabilities:
Derivative liabilities	0		0
Recurring [Member] | MBS Put Options [Member]
Derivative assets:
Derivative assets	2,302		3,170
Recurring [Member] | MBS Put Options [Member] | Level 1 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | MBS Put Options [Member] | Level 2 [Member]
Derivative assets:
Derivative assets	2,302		3,170
Recurring [Member] | MBS Put Options [Member] | Level 3 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | MBS Call Options [Member]
Derivative assets:
Derivative assets	7
Recurring [Member] | MBS Call Options [Member] | Level 1 [Member]
Derivative assets:
Derivative assets	0
Recurring [Member] | MBS Call Options [Member] | Level 2 [Member]
Derivative assets:
Derivative assets	7
Recurring [Member] | MBS Call Options [Member] | Level 3 [Member]
Derivative assets:
Derivative assets	0
Recurring [Member] | Put Options on Interest Rate Futures [Member]
Derivative assets:
Derivative assets	141		656
Recurring [Member] | Put Options on Interest Rate Futures [Member] | Level 1 [Member]
Derivative assets:
Derivative assets	141		656
Recurring [Member] | Put Options on Interest Rate Futures [Member] | Level 2 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Put Options on Interest Rate Futures [Member] | Level 3 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Repurchase Agreement Derivatives [Member]
Derivative assets:
Derivative assets	9,415		3,748
Recurring [Member] | Repurchase Agreement Derivatives [Member] | Level 1 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Repurchase Agreement Derivatives [Member] | Level 2 [Member]
Derivative assets:
Derivative assets	0		0
Recurring [Member] | Repurchase Agreement Derivatives [Member] | Level 3 [Member]
Derivative assets:
Derivative assets	$ 9,415		$ 3,748

Fair Value - Summary of Changes

Fair Value - Summary of Changes in Items Measured Using Level 3 Inputs on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Assets:
Amounts received as proceeds from sales of mortgage loans	$ 96,383	$ 8,655	$ 228,337	$ 28,467
Recurring [Member]
Assets:
Beginning balance	1,827,304	1,577,151	1,984,616	1,726,764
Purchases and issuances	4,612	9,455	21,794	26,445
Repayments and sales	(139,244)	(181,029)	(498,572)	(372,744)
Capitalization of interest	6,037	11,018	18,127	40,748
Capitalization of advances	1,373	4,611	4,733	17,759
ESS received pursuant to a recapture agreement with PFSI	499	1,207	1,983	4,160
Amounts received as proceeds from sales of mortgage loans	108,694	8,655	245,074	28,467
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	4,407	6,035	6,864	23,498
Other factors	24,804	18,827	67,238	71,707
Total	29,211	24,862	74,102	95,205
Transfers of mortgage loans to REO and real estate held for investment	(8,476)	(26,705)	(39,367)	(88,760)
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	722		1,336
Transfers of interest rate lock commitments to mortgage loans acquired for sale	3,792	(23,814)	20,698	(72,633)
Ending balance	1,834,524	1,405,411	1,834,524	1,405,411
Changes in fair value recognized during the quarter relating to assets	5,188	(10,670)	36,238	10,766
Recurring [Member] | Accounting Standards Update 2014-11 Transfers and Servicing [Member]
Assets:
Beginning balance			773,035
Recurring [Member] | Previously Reported [Member]
Assets:
Beginning balance			1,211,581
Recurring [Member] | CRT Agreements [Member]
Assets:
Beginning balance	119,169	52,716	98,640	15,610
Purchases and issuances	0	0	0	0
Repayments and sales	(23,367)	(10,798)	(64,907)	(27,595)
Capitalization of interest	0	0	0	0
Capitalization of advances	0	0	0	0
ESS received pursuant to a recapture agreement with PFSI	0	0	0	0
Amounts received as proceeds from sales of mortgage loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	30,552	14,960	92,621	68,863
Total	30,552	14,960	92,621	68,863
Transfers of mortgage loans to REO and real estate held for investment	0	0	0	0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0	0	0	0
Ending balance	126,354	56,878	126,354	56,878
Changes in fair value recognized during the quarter relating to assets	7,185	4,162	27,714	41,268
Recurring [Member] | Mortgage loans acquired for sale at fair value [Member]
Assets:
Beginning balance	6,540		8,135
Purchases and issuances	2,640		8,243
Repayments and sales	(2,481)		(10,441)
Capitalization of interest	0		0
Capitalization of advances	0		0
ESS received pursuant to a recapture agreement with PFSI	0		0
Amounts received as proceeds from sales of mortgage loans	0		0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0		0
Other factors	(324)		(176)
Total	(324)		(176)
Transfers of mortgage loans to REO and real estate held for investment	0		0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	722		1,336
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0		0
Ending balance	7,097		7,097
Changes in fair value recognized during the quarter relating to assets	(257)		(330)
Recurring [Member] | Interest Rate Lock Commitments [Member]
Assets:
Beginning balance	2,807	395	4,632	3,777
Purchases and issuances	(3,699)	9,264	2,140	26,185
Repayments and sales	0	0	0	0
Capitalization of interest	0	0	0	0
Capitalization of advances	0	0	0	0
ESS received pursuant to a recapture agreement with PFSI	0	0	0	0
Amounts received as proceeds from sales of mortgage loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	(4,001)	15,430	(28,571)	43,946
Total	(4,001)	15,430	(28,571)	43,946
Transfers of mortgage loans to REO and real estate held for investment	0	0	0	0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	3,792	(23,814)	20,698	(72,633)
Ending balance	(1,101)	1,275	(1,101)	1,275
Changes in fair value recognized during the quarter relating to assets	(1,101)	1,275	(1,101)	1,275
Recurring [Member] | Interest-only security payable [Member]
Liabilities:
Beginning balance	7,652	6,577	7,070	4,114
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk\Other factors	1,169	(191)	1,751	2,272
Ending balance	8,821	6,386	8,821	6,386
Changes in fair value recognized during the quarter relating to liability	1,169	(191)	1,751	2,272
Recurring [Member] | Interest-only security payable [Member] | Credit Risk [Member]
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk\Other factors	0	0	0	0
Recurring [Member] | Interest-only security payable [Member] | Other Factors [Member]
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk\Other factors	1,169	(191)	1,751	2,272
Recurring [Member] | Mortgage loans at fair value [Member]
Assets:
Beginning balance	447,473	1,184,620	768,433	1,354,572
Purchases and issuances	0	0	0	0
Repayments and sales	(98,622)	(156,821)	(381,646)	(302,829)
Capitalization of interest	2,297	7,020	6,543	27,737
Capitalization of advances	1,373	4,611	4,733	17,759
ESS received pursuant to a recapture agreement with PFSI	0	0	0	0
Amounts received as proceeds from sales of mortgage loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	4,407	6,035	6,864	23,498
Other factors	(7,458)	(2,758)	(24,566)	(15,975)
Total	(3,051)	3,277	(17,702)	7,523
Transfers of mortgage loans to REO and real estate held for investment	(8,476)	(26,705)	(39,367)	(88,760)
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0	0	0	0
Ending balance	340,994	1,016,002	340,994	1,016,002
Changes in fair value recognized during the quarter relating to assets	(6,711)	(7,302)	(18,170)	(6,650)
Recurring [Member] | Excess servicing spread [Member]
Assets:
Beginning balance	229,470	261,796	236,534	288,669
Purchases and issuances	0	0	0	0
Repayments and sales	(11,543)	(13,410)	(35,852)	(42,320)
Capitalization of interest	3,740	3,998	11,584	13,011
Capitalization of advances	0	0	0	0
ESS received pursuant to a recapture agreement with PFSI	499	1,207	1,983	4,160
Amounts received as proceeds from sales of mortgage loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	1,109	(4,828)	9,026	(14,757)
Total	1,109	(4,828)	9,026	(14,757)
Transfers of mortgage loans to REO and real estate held for investment	0	0	0	0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0	0	0	0
Ending balance	223,275	248,763	223,275	248,763
Changes in fair value recognized during the quarter relating to assets	1,109	(4,828)	9,026	(14,757)
Recurring [Member] | Firm commitment to purchase CRT security [Member]
Assets:
Beginning balance	4,426		0
Purchases and issuances	0		0
Repayments and sales	0		0
Capitalization of interest	0		0
Capitalization of advances	0		0
ESS received pursuant to a recapture agreement with PFSI	0		0
Amounts received as proceeds from sales of mortgage loans	12,311		16,737
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0		0
Other factors	2,012		2,012
Total	2,012		2,012
Transfers of mortgage loans to REO and real estate held for investment	0		0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0		0
Ending balance	18,749		18,749
Changes in fair value recognized during the quarter relating to assets	2,012		2,012
Recurring [Member] | Mortgage Servicing Rights
Assets:
Beginning balance	1,010,507	77,624	864,494	64,136
Purchases and issuances	0	10	0	79
Repayments and sales	(100)	0	(100)	0
Capitalization of interest	0	0	0	0
Capitalization of advances	0	0	0	0
ESS received pursuant to a recapture agreement with PFSI	0	0	0	0
Amounts received as proceeds from sales of mortgage loans	96,383	8,655	228,337	28,467
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	2,951	(3,977)	17,010	(10,370)
Total	2,951	(3,977)	17,010	(10,370)
Transfers of mortgage loans to REO and real estate held for investment	0	0	0	0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0	0	0	0
Ending balance	1,109,741	82,312	1,109,741	82,312
Changes in fair value recognized during the quarter relating to assets	2,951	(3,977)	17,010	(10,370)
Recurring [Member] | Mortgage Servicing Rights | Accounting Standards Update 2014-11 Transfers and Servicing [Member]
Assets:
Beginning balance			773,035
Recurring [Member] | Mortgage Servicing Rights | Previously Reported [Member]
Assets:
Beginning balance			91,459
Recurring [Member] | Repurchase Agreement Derivatives [Member]
Assets:
Beginning balance	6,912	0	3,748	0
Purchases and issuances	5,671	181	11,411	181
Repayments and sales	(3,131)	0	(5,626)	0
Capitalization of interest	0	0	0	0
Capitalization of advances	0	0	0	0
ESS received pursuant to a recapture agreement with PFSI	0	0	0	0
Amounts received as proceeds from sales of mortgage loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	(37)	0	(118)	0
Total	(37)	0	(118)	0
Transfers of mortgage loans to REO and real estate held for investment	0	0	0	0
Transfers of mortgage loans acquired for sale at fair value from "Level 2" to "Level 3" (2)	0		0
Transfers of interest rate lock commitments to mortgage loans acquired for sale	0	0	0	0
Ending balance	9,415	181	9,415	181
Changes in fair value recognized during the quarter relating to assets	$ 0	$ 0	$ 77	$ 0

Fair Value - Fair Values and Re

Fair Value - Fair Values and Related Principal Amounts Due upon Maturity of Mortgage Loans Accounted for Under Fair Value Option (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value Option Loans Held As Assets [Abstract]
Fair value option loans held as assets, Total	$ 633,168	$ 1,089,473
Mortgage loans at fair value	633,168	1,089,473
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Unpaid principal balance of loans outstanding at period-end	788,026	1,360,642
Unpaid principal balance	788,026	1,360,642
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	(154,858)	(271,169)
Mortgage loans acquired for sale at fair value [Member]
Fair Value Option Loans Held As Assets [Abstract]
Fair value option loans held as assets ninety days or less past due	1,949,285	1,268,121
Not in foreclosure	147	950
In foreclosure	0	444
Fair value option loans held as assets, Total	147	1,394
Mortgage loans at fair value	1,949,432	1,269,515
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Mortgage loans on real estate principal amount of delinquent loans less than ninety days	1,900,556	1,221,125
Not in foreclosure	187	1,120
In foreclosure	0	496
Unpaid principal balance of loans outstanding at period-end	1,900,743	1,222,741
Fair value option loans held as assets ninety days or less past due aggregate difference	48,729	46,996
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Not in foreclosure	(40)	(170)
In foreclosure	0	(52)
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	48,689	46,774
Mortgage loans acquired for sale at fair value [Member] | Nonperforming mortgage loans [Member]
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Unpaid principal balance of loans outstanding at period-end	187	1,616
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	(40)	(222)
Mortgage Loans at Fair Value Held in Consolidated VIE [Member]
Fair Value Option Loans Held As Assets [Abstract]
Fair value option loans held as assets ninety days or less past due	292,174	321,040
Not in foreclosure	0	0
In foreclosure	0	0
Mortgage loans at fair value	292,174	321,040
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Mortgage loans on real estate principal amount of delinquent loans less than ninety days	299,843	316,684
Not in foreclosure	0	0
In foreclosure	0	0
Unpaid principal balance	299,843	316,684
Fair value option loans held as assets ninety days or less past due aggregate difference	(7,669)	4,356
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Not in foreclosure	0	0
In foreclosure	0	0
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	(7,669)	4,356
Mortgage Loans at Fair Value Held in Consolidated VIE [Member] | Nonperforming mortgage loans [Member]
Fair Value Option Loans Held As Assets [Abstract]
Mortgage loans at fair value	0	0
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Unpaid principal balance	0	0
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	0	0
Mortgage Loans and Mortgage Loans under Forward Purchase Agreements at Fair Value [Member]
Fair Value Option Loans Held As Assets [Abstract]
Fair value option loans held as assets ninety days or less past due	200,176	414,785
Not in foreclosure	66,791	166,749
In foreclosure	74,027	186,899
Mortgage loans at fair value	340,994	768,433
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Mortgage loans on real estate principal amount of delinquent loans less than ninety days	261,808	519,009
Not in foreclosure	113,308	257,038
In foreclosure	113,067	267,911
Unpaid principal balance	488,183	1,043,958
Fair value option loans held as assets ninety days or less past due aggregate difference	(61,632)	(104,224)
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Not in foreclosure	(46,517)	(90,289)
In foreclosure	(39,040)	(81,012)
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	(147,189)	(275,525)
Mortgage Loans and Mortgage Loans under Forward Purchase Agreements at Fair Value [Member] | Nonperforming mortgage loans [Member]
Fair Value Option Loans Held As Assets [Abstract]
Mortgage loans at fair value	140,818	353,648
Mortgage Loans On Real Estate Other Required Disclosures [Abstract]
Unpaid principal balance	226,375	524,949
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due, Aggregate Difference
Fair Value, Option, Loans Held as Assets, Aggregate Difference, Total	$ (85,557)	$ (171,301)

Fair Value - Summary of Chang_2

Fair Value - Summary of Changes in Fair Value Included in Current Period Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest-only security payable at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	$ (1,169)	$ 191	$ (1,751)	$ (2,272)
Interest-only security payable at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Interest-only security payable at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Interest-only security payable at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(1,169)	191	(1,751)	(2,272)
Interest-only security payable at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Asset-Backed Financing of the VIE at Fair Value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	3,315	(2,893)	12,584	(7,388)
Asset-Backed Financing of the VIE at Fair Value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Asset-Backed Financing of the VIE at Fair Value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Asset-Backed Financing of the VIE at Fair Value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	3,516	(2,158)	12,658	(5,581)
Asset-Backed Financing of the VIE at Fair Value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(201)	(735)	(74)	(1,807)
Liabilities, Total [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,146	(2,702)	10,833	(9,660)
Liabilities, Total [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Liabilities, Total [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Liabilities, Total [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,347	(1,967)	10,907	(7,853)
Liabilities, Total [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(201)	(735)	(74)	(1,807)
Short-term investments at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Short-term investments at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Short-term investments at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Short-term investments at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Short-term investments at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage-backed securities at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(20,259)	3,520	(52,911)	4,892
Mortgage-backed securities at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage-backed securities at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage-backed securities at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(19,030)	5,001	(50,288)	9,168
Mortgage-backed securities at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(1,229)	(1,481)	(2,623)	(4,276)
Firm commitment to purchase CRT security [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	14,323		18,749
Firm commitment to purchase CRT security [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0		0
Firm commitment to purchase CRT security [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	12,311		16,737
Firm commitment to purchase CRT security [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,012		2,012
Firm commitment to purchase CRT security [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0		0
Mortgage loans acquired for sale at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	751	32,935	(27,397)	83,839
Mortgage loans acquired for sale at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage loans acquired for sale at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	751	32,935	(27,397)	83,839
Mortgage loans acquired for sale at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage loans acquired for sale at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage loans at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(4,223)	13,032	(23,185)	43,027
Mortgage loans at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage loans at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Mortgage loans at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(6,681)	5,415	(29,694)	13,832
Mortgage loans at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,458	7,617	6,509	29,195
Excess servicing spread [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	4,849	(830)	20,610	(1,746)
Excess servicing spread [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Excess servicing spread [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Excess servicing spread [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	1,109	(4,828)	9,026	(14,757)
Excess servicing spread [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	3,740	3,998	11,584	13,011
MSRs at fair value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,951	(3,977)	17,010	(10,370)
MSRs at fair value [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,951	(3,977)	17,010	(10,370)
MSRs at fair value [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
MSRs at fair value [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
MSRs at fair value [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	0	0	0	0
Assets, Total [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(1,608)	44,680	(47,124)	119,642
Assets, Total [Member] | Net Mortgage Loan Servicing Fees [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	2,951	(3,977)	17,010	(10,370)
Assets, Total [Member] | Net Gain on Mortgage Loans Acquired for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	13,062	32,935	(10,660)	83,839
Assets, Total [Member] | Net Gain (Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	(22,590)	5,588	(68,944)	8,243
Assets, Total [Member] | Net Interest Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value included in current period income	$ 4,969	$ 10,134	$ 15,470	$ 37,930

Fair Value - Summary of Finan_2

Fair Value - Summary of Financial Statement Items Re-measured at Fair Value on Nonrecurring Basis (Detail) - Nonrecurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate acquired in settlement of loans	$ 37,722	$ 71,380
Total Assets	37,722	384,375
MSRs at lower of amortized cost or fair value		312,995
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate acquired in settlement of loans	0	0
Total Assets	0	0
MSRs at lower of amortized cost or fair value		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate acquired in settlement of loans	0	0
Total Assets	0	0
MSRs at lower of amortized cost or fair value		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate acquired in settlement of loans	37,722	71,380
Total Assets	$ 37,722	384,375
MSRs at lower of amortized cost or fair value		$ 312,995

Fair Value - Summary of Chang_3

Fair Value - Summary of Changes in Fair Value Recognized in Assets that Measured at Fair Value on a Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs at lower of amortized cost or fair value		$ 1,702	$ 0	$ 4,287
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate asset acquired in settlement of loans	$ (2,285)	(5,666)	(6,209)	(7,454)
MSRs at lower of amortized cost or fair value	0	(1,702)	0	(4,287)
Total assets, gains (losses) recognized	$ (2,285)	$ (7,368)	$ (6,209)	$ (11,741)

Fair Value - Quantitative Summa

Fair Value - Quantitative Summary of Key Inputs Used in Valuation of Level 3 Mortgage Loans at Fair Value (Detail) - Mortgage loans at fair value [Member]	Sep. 30, 2018	Dec. 31, 2017
Discount Rate [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.028	0.029
Discount Rate [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.167	0.150
Discount Rate [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.073	0.069
Twelve-Month Projected Housing Price Index Change [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.035	0.036
Twelve-Month Projected Housing Price Index Change [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.044	0.046
Twelve-Month Projected Housing Price Index Change [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.041	0.044
Prepayment Speed [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.025	0.032
Prepayment Speed [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.081	0.110
Prepayment Speed [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.041	0.042
Total Prepayment Speed [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.104	0.108
Total Prepayment Speed [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.223	0.238
Total Prepayment Speed [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.156	0.165

Fair Value - Summary of Key Inp

Fair Value - Summary of Key Inputs Used in Determining Fair Value of ESS (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
UPB of underlying mortgage loans (in thousands)	$ 8,290,310	$ 794,770	$ 18,687,615	$ 2,613,258
Average servicing fee rate (in basis points)	0.25%	0.25%	0.26%	0.25%
Excess servicing spread [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
UPB of underlying mortgage loans (in thousands)			$ 24,058,366		$ 27,217,199
Average servicing fee rate (in basis points)			0.34%		0.34%
Average ESS rate (in basis points)			0.19%		0.19%
Pricing spread			3.70%		4.10%
Annual total prepayment speed			9.00%		10.80%
Life (in years)			7 years 1 month 6 days		6 years 6 months
Excess servicing spread [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Pricing spread			3.40%		3.80%
Annual total prepayment speed			7.50%		8.40%
Life (in years)			1 year 4 months 24 days		1 year 4 months 24 days
Excess servicing spread [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Pricing spread			3.90%		4.30%
Annual total prepayment speed			38.40%		41.40%
Life (in years)			8 years		7 years 8 months 12 days

Fair Value - Schedule of Key In

Fair Value - Schedule of Key Inputs Used in Determining Fair Value of Firm Commitment to Purchase Credit Risk Transfer Security (Detail) - Firm commitment to purchase CRT security [Member]	Sep. 30, 2018
Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.082
Voluntary Prepayment Speed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.120
Involuntary Prepayment Speed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.001

Fair Value - Quantitative Sum_2

Fair Value - Quantitative Summary of Key Unobservable Inputs Used in Valuation of Interest Rate Lock Commitments (Detail)	Sep. 30, 2018	Dec. 31, 2017
Pull-Through Rate [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	43.80%	58.00%
Pull-Through Rate [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	100.00%	100.00%
Pull-Through Rate [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	92.60%	90.30%
Servicing Fee Multiple [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	2.50%	2.10%
Servicing Fee Multiple [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	5.90%	5.80%
Servicing Fee Multiple [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	4.70%	4.90%
Percentage of UPB [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	0.80%	0.00%
Percentage of UPB [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	2.80%	2.40%
Percentage of UPB [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	1.40%	1.30%

Fair Value - Quantitative Sum_3

Fair Value - Quantitative Summary of Key Unobservable Inputs Used in Valuation of Non-securitized CRT Agreements (Detail) - CRT Agreements [Member]	Sep. 30, 2018	Dec. 31, 2017
Discount Rate [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	5.8	5.1
Discount Rate [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	6.7	6.2
Discount Rate [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	6.2	5.6
Voluntary Prepayment Speed [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	7.5	12.1
Voluntary Prepayment Speed [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	8.7	15
Voluntary Prepayment Speed [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.081	0.130
Involuntary Prepayment Speed [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.2	0.3
Involuntary Prepayment Speed [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.3	0.3
Involuntary Prepayment Speed [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation	0.003	0.003

Fair Value - Key Assumptions Us

Fair Value - Key Assumptions Used in Determining Fair Value of MSRs at Time of Initial Recognition (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, MSR recognized	$ 96,383,000	$ 8,655,000	$ 228,337,000	$ 28,467,000
Fair value, UPB of underlying mortgage loans	$ 8,290,310,000	$ 794,770,000	$ 18,687,615,000	$ 2,613,258,000
Fair value, Weighted-average annual servicing fee rate (in basis points)	0.25%	0.25%	0.26%	0.25%
Amortized cost, MSR recognized		$ 74,183,000	$ 0	$ 178,894,000
Amortized cost, UPB of underlying mortgage loans		$ 6,050,337,000		$ 14,624,151,000
Amortized cost, Weighted-average annual servicing fee rate (in basis points)		0.25%		0.25%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, Pricing spread during period	7.30%	7.60%	7.30%	7.60%
Fair value inputs, Annual prepayment speed during period	3.50%	8.30%	3.20%	7.90%
Fair value inputs, Weighted average life during period	2 years 3 months 18 days	2 years 9 months 18 days	2 years 3 months 18 days	2 years 9 months 18 days
Fair value inputs, Annual per loan cost of servicing during period	$ 77,000	$ 79,000	$ 77,000	$ 79,000
Amortized cost, Pricing spread during period		7.60%		7.60%
Amortized cost, Annual prepayment speed during period		3.50%		3.20%
Amortized cost, Life (in years)		2 years 7 months 6 days		2 years 7 months 6 days
Amortized cost, Annual per loan cost of servicing during period		$ 79,000		$ 79,000
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, Pricing spread during period	12.90%	7.60%	12.90%	7.60%
Fair value inputs, Annual prepayment speed during period	34.60%	29.50%	34.60%	29.50%
Fair value inputs, Weighted average life during period	11 years 8 months 12 days	8 years 6 months	11 years 10 months 24 days	8 years 6 months
Fair value inputs, Annual per loan cost of servicing during period	$ 79,000	$ 79,000	$ 79,000	$ 79,000
Amortized cost, Pricing spread during period		12.60%		12.60%
Amortized cost, Annual prepayment speed during period		31.10%		31.10%
Amortized cost, Life (in years)		11 years 2 months 12 days		11 years 10 months 24 days
Amortized cost, Annual per loan cost of servicing during period		$ 79,000		$ 79,000
Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, Pricing spread during period	7.30%	7.60%	7.40%	7.60%
Fair value inputs, Annual prepayment speed during period	10.60%	10.50%	9.60%	10.70%
Fair value inputs, Weighted average life during period	7 years 3 months 18 days	7 years 4 months 24 days	7 years 8 months 12 days	7 years 3 months 18 days
Fair value inputs, Annual per loan cost of servicing during period	$ 79,000	$ 79,000	$ 79,000	$ 79,000
Amortized cost, Pricing spread during period		7.60%		7.60%
Amortized cost, Annual prepayment speed during period		8.10%		8.10%
Amortized cost, Life (in years)		8 years 4 months 24 days		8 years 3 months 18 days
Amortized cost, Annual per loan cost of servicing during period		$ 79,000		$ 79,000

Fair Value - Quantitative Sum_4

Fair Value - Quantitative Summary of Key Assumptions Used in Valuation of MSRs as of Dates Presented, and Effect on Estimated Fair Value from Adverse Changes in Those Inputs (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at end of period	$ 1,109,741,000	$ 91,459,000	$ 1,010,507,000	$ 82,312,000	$ 77,624,000	$ 64,136,000
UPB of underlying mortgage loans, Fair Value	$ 84,351,431,000	$ 8,273,696,000
Weighted-average annual servicing fee rate (in basis points), Fair value input	0.25%	0.25%
Weighted-average note interest rate, Fair value	4.10%	4.70%
Effect on fair value of 5% adverse change, Fair value input, Pricing spread	$ (16,686,000)	$ (1,347,000)
Effect on fair value of 10% adverse change, Fair value input, Pricing spread	(32,897,000)	(2,655,000)
Effect on fair value of 20% adverse change, Fair value input, Pricing spread	(63,970,000)	(5,162,000)
Effect on fair value of 5% adverse change, Fair value input, Prepayment speed	(15,209,000)	(1,954,000)
Effect on fair value of 10% adverse change, Fair value input, Prepayment speed	(29,926,000)	(3,827,000)
Effect on fair value of 20% adverse change, Fair value input, Prepayment speed	(57,978,000)	(7,352,000)
Effect on fair value of 5% adverse change, Fair value input, Annual per-loan cost of servicing	(7,834,000)	(744,000)
Effect on fair value of 10% adverse change, Fair value input, Annual per-loan cost of servicing	(15,668,000)	(1,488,000)
Effect on fair value of 20% adverse change, Fair value input, Annual per-loan cost of servicing	(31,337,000)	(2,976,000)
Carrying value, Amortized cost	$ 0	753,322,000		$ 708,023,000
UPB of underlying mortgage loans, Amortized cost		$ 63,853,606,000
Weighted-average annual servicing fee rate (in basis points), Amortized cost		0.25%
Weighted-average note interest rate, Amortized cost		3.90%
Effect on fair value of 5% adverse change, Amortized cost, Pricing spread		$ (11,848,000)
Effect on fair value of 10% adverse change, Amortized cost, Pricing spread		(23,352,000)
Effect on fair value of 20% adverse change, Amortized cost, Pricing spread		(45,379,000)
Effect on fair value of 5% adverse change, Amortized cost, Prepayment speed		(12,267,000)
Effect on fair value of 10% adverse change, Amortized cost, Prepayment speed		(24,120,000)
Effect on fair value of 20% adverse change, Amortized cost, Prepayment speed		(46,668,000)
Effect on fair value of 5% adverse change, Amortized cost, Annual per-loan cost of servicing		(5,721,000)
Effect on fair value of 10% adverse change, Amortized cost, Annual per-loan cost of servicing		(11,441,000)
Effect on fair value of 20% adverse change, Amortized cost, Annual per-loan cost of servicing		$ (22,883,000)
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Pricing spread	7.30%	7.60%
Estimated fair value inputs, Prepayment speed	6.20%	7.30%
Estimated fair value inputs, Annual per-loan cost of servicing	$ 78,000	$ 77,000
Amortized cost, Pricing spread		7.60%
Amortized cost, Prepayment speed		7.10%
Amortized cost, Weighted average life (in years)		2 years 10 months 24 days
Amortized cost, Annual per-loan cost of servicing		$ 78,000
Minimum [Member] | Mortgage service rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Weighted average life (in years)	2 years 10 months 24 days	3 years 1 month 6 days
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Pricing spread	12.90%	12.60%
Estimated fair value inputs, Prepayment speed	24.30%	20.90%
Estimated fair value inputs, Annual per-loan cost of servicing	$ 79,000	$ 79,000
Amortized cost, Pricing spread		13.10%
Amortized cost, Prepayment speed		27.10%
Amortized cost, Weighted average life (in years)		8 years
Amortized cost, Annual per-loan cost of servicing		$ 79,000
Maximum [Member] | Mortgage service rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Weighted average life (in years)	8 years 6 months	6 years 9 months 18 days
Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Pricing spread	7.30%	7.60%
Estimated fair value inputs, Prepayment speed	7.60%	11.10%
Estimated fair value inputs, Annual per-loan cost of servicing	$ 79,000	$ 79,000
Amortized cost, Pricing spread		7.60%
Amortized cost, Prepayment speed		8.40%
Amortized cost, Weighted average life (in years)		7 years 7 months 6 days
Amortized cost, Annual per-loan cost of servicing		$ 79,000
Weighted Average [Member] | Mortgage service rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value inputs, Weighted average life (in years)	8 years 1 month 6 days	6 years 9 months 18 days

Mortgage Backed Securities - Su

Mortgage Backed Securities - Summary of Mortgage Backed Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Mortgage Backed Securities [Line Items]
Fair value	$ 2,126,507	$ 989,461
Mortgage Backed Securities [Member]
Mortgage Backed Securities [Line Items]
Principal balance	2,135,431	961,600
Net premiums	47,376	33,873
Accumulated valuation changes	56,300	6,012
Fair value	2,126,507	989,461
Fannie Mae [Member] | Mortgage Backed Securities [Member]
Mortgage Backed Securities [Line Items]
Principal balance	1,592,192	774,473
Net premiums	40,413	30,355
Accumulated valuation changes	46,691	7,975
Fair value	1,585,914	796,853
Freddie Mac [Member] | Mortgage Backed Securities [Member]
Mortgage Backed Securities [Line Items]
Principal balance	543,239	187,127
Net premiums	6,963	3,518
Accumulated valuation changes	9,609	(1,963)
Fair value	$ 540,593	$ 192,608

Mortgage Loans Acquired for S_3

Mortgage Loans Acquired for Sale at Fair Value - Summary of Distribution of Company's Mortgage Loans Acquired for Sale at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	$ 1,949,432	$ 1,269,515
Mortgage loans pledged to secure: Assets sold under agreements to repurchase	1,930,547	1,249,277
Mortgage loans pledged to secure total	1,930,547	1,249,277
Penny Mac Loan Services Llc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	217,334	279,571
Mortgage Loans Acquired for Sale [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans pledged to secure: Assets sold under agreements to repurchase	1,898,155	1,201,992
Mortgage loans pledged to secure mortgage loan participation purchase and sale agreements	32,392	47,285
Agency-Eligible [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	1,708,928	971,910
Held for Sale to PLS - Government-Insured or Guaranteed [Member] | Penny Mac Loan Services Llc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	217,334	279,571
Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	8,500	9,898
Jumbo [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	7,573	0
Repurchased Pursuant to Representations and Warranties [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans acquired for sale at fair value	$ 7,097	$ 8,136

Mortgage Loans Acquired for S_4

Mortgage Loans Acquired for Sale at Fair Value - Additional Information (Detail) - Penny Mac Loan Services Llc	9 Months Ended
	Sep. 30, 2018
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sourcing fee on average number of calendar days mortgage loans are held prior to purchase by PLS	0.02%
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sourcing fee on average number of calendar days mortgage loans are held prior to purchase by PLS	0.035%

Mortgage Loans at Fair Value -

Mortgage Loans at Fair Value - Summary of Distribution of Company's Mortgage Loans at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Fair value	$ 633,168	$ 1,089,473
Unpaid principal balance	788,026	1,360,642
Asset-backed financing of a VIE at fair value	292,174	321,040
Mortgage loans at fair value pledged to secure	624,267	1,081,893
Mortgage loans acquired for sale at fair value [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	1,949,432	1,269,515
Assets sold under agreements to repurchase	332,093	760,853
Fixed interest rate jumbo mortgage loans held in a VIE [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	292,174	321,040
Unpaid principal balance	299,843	316,684
Distressed mortgage loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	340,994	768,433
Unpaid principal balance	488,183	1,043,958
Distressed mortgage loans [Member] | Nonperforming mortgage loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	140,818	353,648
Unpaid principal balance	226,375	524,949
Distressed mortgage loans [Member] | Performing mortgage loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	200,176	414,785
Unpaid principal balance	261,808	519,009
Distressed mortgage loans [Member] | Performing mortgage loans [Member] | Interest rate step-up [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	125,063	189,724
Unpaid principal balance	170,066	242,335
Distressed mortgage loans [Member] | Performing mortgage loans [Member] | Fixed interest rate [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	58,179	186,929
Unpaid principal balance	73,769	236,840
Distressed mortgage loans [Member] | Performing mortgage loans [Member] | Adjustable-rate/hybrid [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value	16,934	38,132
Unpaid principal balance	$ 17,973	$ 39,834

Mortgage Loans at Fair Value _2

Mortgage Loans at Fair Value - Summary of Certain Concentrations of Credit Risk in Portfolio of Distressed Mortgage Loans at Fair Value (Detail)	Sep. 30, 2018	Dec. 31, 2017
Risks And Uncertainties [Abstract]
Portion of mortgage loans originated between 2005 and 2007	71.00%	73.00%
Mortgage loans with unpaid-principal balance-to-current -property-value in excess of 100%	31.00%	38.00%

Mortgage Loans at Fair Value _3

Mortgage Loans at Fair Value - Summary of Certain Concentrations of Credit Risk in Portfolio of Distressed Mortgage Loans at Fair Value (Parenthetical) (Detail)	Sep. 30, 2018	Dec. 31, 2017
Risks And Uncertainties [Abstract]
Percentage of mortgage loans	100.00%	100.00%
Percentage of contribution by states in mortgage loans	5.00%	5.00%

Derivative Activities - Additio

Derivative Activities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018
Derivatives Fair Value [Line Items]
Maturity date description	The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Master Repurchase Agreement [Member]
Derivatives Fair Value [Line Items]
Maturity date description	The master repurchase agreement is subject to a rolling six month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Master Repurchase Agreement [Member] | Embedded Derivatives [Member]
Derivatives Fair Value [Line Items]
Maturity date description	The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier by the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity

Derivative Activities - Derivat

Derivative Activities - Derivative Assets and Liabilities Recorded within Derivative Assets and Derivative Liabilities and Related Margin Deposits Recorded in Other Assets (Detail) - USD ($)	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Total derivative assets instruments before netting	$ 161,535,000		$ 115,803,000
Derivative assets, Netting	(17,958,000)		(1,922,000)
Total derivative assets after netting	143,577,000		113,881,000
Margin deposits placed with (from) derivatives counterparties included in Other assets, net	(12,736,000)		76,000
Derivative assets pledged to secure Assets sold under agreements to repurchase	27,710,000		26,058,000
Total derivative liabilities	17,101,000		3,305,000
Derivative liabilities, Netting	(5,221,000)		(1,999,000)
Total derivative liabilities after netting	11,880,000		1,306,000
Repurchase Agreement Derivatives [Member]
Derivatives Fair Value [Line Items]
Notional amount	0		0
Total derivative assets instruments before netting	9,415,000		3,748,000
Derivative assets, Netting	0		0
Total derivative assets after netting	9,415,000		3,748,000
Total derivative liabilities	0		0
CRT Agreements [Member]
Derivatives Fair Value [Line Items]
Notional amount	30,648,306,000		26,845,392,000
Total derivative assets instruments before netting	126,354,000		98,640,000
Derivative assets, Netting	0		0
Total derivative assets after netting	126,354,000		98,640,000
Total derivative liabilities	0		0
Interest Rate Lock Commitments [Member]
Derivatives Fair Value [Line Items]
Notional amount	1,682,007,000		1,250,803,000
Total derivative assets instruments before netting	2,317,000		4,859,000
Total derivative assets after netting	2,317,000		4,859,000
Total derivative liabilities	3,418,000		227,000
Forward Purchase Contracts [Member]
Derivatives Fair Value [Line Items]
Notional amount	3,350,125,000	$ 2,628,934,000	1,996,235,000	$ 1,598,412,000	$ 1,933,390,000	$ 4,840,707,000
Total derivative assets instruments before netting	1,761,000		4,343,000
Derivative assets, Netting	0		0
Total derivative assets after netting	1,761,000		4,343,000
Total derivative liabilities	11,964,000		248,000
Forward Sale Contracts [Member]
Derivatives Fair Value [Line Items]
Notional amount	5,124,927,000	3,793,355,000	2,565,271,000	2,808,847,000	3,644,636,000	6,148,242,000
Total derivative assets instruments before netting	19,238,000		387,000
Derivative assets, Netting	0		0
Total derivative assets after netting	19,238,000		387,000
Total derivative liabilities	1,719,000		2,830,000
MBS Call Options [Member]
Derivatives Fair Value [Line Items]
Notional amount	750,000,000	0	0	75,000,000	200,000,000	750,000,000
Total derivative assets instruments before netting	7,000		0
Derivative assets, Netting	0		0
Total derivative assets after netting	7,000		0
Total derivative liabilities	0		0
MBS Put Options [Member]
Derivatives Fair Value [Line Items]
Notional amount	2,600,000,000	1,550,000,000	2,375,000,000	1,125,000,000	1,475,000,000	925,000,000
Total derivative assets instruments before netting	2,302,000		3,170,000
Derivative assets, Netting	0		0
Total derivative assets after netting	2,302,000		3,170,000
Total derivative liabilities	0		0
Put Options on Interest Rate Futures [Member]
Derivatives Fair Value [Line Items]
Notional amount	100,000,000	600,000,000	550,000,000	475,000,000	925,000,000	550,000,000
Total derivative assets instruments before netting	141,000		656,000
Derivative assets, Netting	0		0
Total derivative assets after netting	141,000		656,000
Total derivative liabilities	0		0
Swap Futures [Member]
Derivatives Fair Value [Line Items]
Notional amount	0		275,000,000	275,000,000	175,000,000	150,000,000
Total derivative assets instruments before netting	0		0
Total derivative liabilities	0		0
Bond Futures [Member]
Derivatives Fair Value [Line Items]
Notional amount	815,000,000	815,000,000	0
Total derivative assets instruments before netting	0		0
Total derivative liabilities	0		0
Eurodollar Future Sale Contracts [Member]
Derivatives Fair Value [Line Items]
Notional amount	30,000,000	$ 35,000,000	937,000,000	$ 1,038,000,000	$ 1,139,000,000	$ 1,351,000,000
Total derivative assets instruments before netting	0		0
Total derivative liabilities	$ 0		$ 0

Derivative Activities - Summary

Derivative Activities - Summary of Activity in Notional Amount for Derivative Contracts (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Forward Purchase Contracts [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	$ 2,628,934,000	$ 1,933,390,000	$ 1,996,235,000	$ 4,840,707,000
Additions	26,864,290,000	20,560,886,000	67,406,528,000	54,953,063,000
Dispositions/expirations	(26,143,099,000)	(20,895,864,000)	(66,052,638,000)	(58,195,358,000)
Amount, end of quarter	3,350,125,000	1,598,412,000	3,350,125,000	1,598,412,000
Forward Sale Contracts [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	3,793,355,000	3,644,636,000	2,565,271,000	6,148,242,000
Additions	36,205,542,000	27,214,513,000	88,131,417,000	73,030,446,000
Dispositions/expirations	(34,873,970,000)	(28,050,302,000)	(85,571,761,000)	(76,369,841,000)
Amount, end of quarter	5,124,927,000	2,808,847,000	5,124,927,000	2,808,847,000
MBS Put Options [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	1,550,000,000	1,475,000,000	2,375,000,000	925,000,000
Additions	1,050,000,000	3,200,000,000	9,625,000,000	5,125,000,000
Dispositions/expirations	0	(3,550,000,000)	(9,400,000,000)	(4,925,000,000)
Amount, end of quarter	2,600,000,000	1,125,000,000	2,600,000,000	1,125,000,000
MBS Call Options [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	0	200,000,000	0	750,000,000
Additions	750,000,000	275,000,000	750,000,000	475,000,000
Dispositions/expirations	0	(400,000,000)	0	(1,150,000,000)
Amount, end of quarter	750,000,000	75,000,000	750,000,000	75,000,000
Call Options on Interest Rate Futures [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	50,000,000	200,000,000	0	200,000,000
Additions	200,000,000	450,000,000	525,000,000	575,000,000
Dispositions/expirations	(250,000,000)	(400,000,000)	(525,000,000)	(525,000,000)
Amount, end of quarter	0	250,000,000	0	250,000,000
Put Options on Interest Rate Futures [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	600,000,000	925,000,000	550,000,000	550,000,000
Additions	1,300,000,000	2,500,000,000	11,700,000,000	5,875,000,000
Dispositions/expirations	(1,800,000,000)	(2,950,000,000)	(12,150,000,000)	(5,950,000,000)
Amount, end of quarter	100,000,000	475,000,000	100,000,000	475,000,000
Bond Futures [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	815,000,000		0
Additions	2,205,000,000		3,020,000,000
Dispositions/expirations	(2,205,000,000)		(2,205,000,000)
Amount, end of quarter	815,000,000		815,000,000
Eurodollar Future Sales Contracts [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter	35,000,000	1,139,000,000	937,000,000	1,351,000,000
Additions	5,000,000	202,000,000	119,597,000	303,000,000
Dispositions/expirations	(10,000,000)	(303,000,000)	(1,026,597,000)	(616,000,000)
Amount, end of quarter	30,000,000	1,038,000,000	30,000,000	1,038,000,000
Treasury Future Buy Contracts [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter		0		0
Additions		55,000,000		110,700,000
Dispositions/expirations		(55,000,000)		(110,700,000)
Amount, end of quarter		0		0
Treasury Future Sale Contracts [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter		0		0
Additions		55,000,000		110,700,000
Dispositions/expirations		(55,000,000)		(110,700,000)
Amount, end of quarter		0		0
Swap Futures [Member]
Derivatives Fair Value [Line Items]
Amount, beginning of quarter		175,000,000	275,000,000	150,000,000
Additions		100,000,000	0	950,000,000
Dispositions/expirations		0	(275,000,000)	(825,000,000)
Amount, end of quarter	$ 0	$ 275,000,000	$ 0	$ 275,000,000

Derivative Activities - Summa_2

Derivative Activities - Summary of Net Derivative Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Assets [Line Items]
Gross amounts of recognized assets	$ 161,535	$ 115,803
Gross amounts offset in the consolidated balance sheet	(17,958)	(1,922)
Total derivative assets after netting	143,577	113,881
Net amounts of assets presented in the consolidated balance sheet	(17,958)	(1,922)
Repurchase Agreement Derivatives [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	9,415	3,748
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	9,415	3,748
CRT Agreement Derivatives [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	126,354	98,640
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	126,354	98,640
Interest Rate Lock Commitments [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	2,317	4,859
Total derivative assets after netting	2,317	4,859
Forward Purchase Contracts [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	1,761	4,343
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	1,761	4,343
Forward Sale Contracts [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	19,238	387
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	19,238	387
Derivatives Not Subject To Master Netting Adjustment [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	138,086	107,247
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	138,086	107,247
Derivatives Not Subject To Master Netting Adjustment [Member] | Interest Rate Lock Commitments [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	2,317	4,859
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	2,317	4,859
MBS Call Options [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	7	0
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	7	0
MBS Put Options [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	2,302	3,170
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	2,302	3,170
Put Options on Interest Rate Futures [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	141	656
Gross amounts offset in the consolidated balance sheet	0	0
Total derivative assets after netting	141	656
Netting [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	0	0
Gross amounts offset in the consolidated balance sheet	(17,958)	(1,922)
Total derivative assets after netting	(17,958)	(1,922)
Derivatives Subject to Master Netting Arrangements [Member]
Offsetting Assets [Line Items]
Gross amounts of recognized assets	23,449	8,556
Gross amounts offset in the consolidated balance sheet	(17,958)	(1,922)
Total derivative assets after netting	$ 5,491	$ 6,634

Derivative Activities - Summa_3

Derivative Activities - Summary of Derivative Assets, Financial Instruments and Collateral Held by Counterparty (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Assets [Line Items]
Total derivative assets after netting	$ 143,577	$ 113,881
Financial instruments	0	0
Cash collateral received	0	0
Net amount	143,577	113,881
CRT Agreements [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	126,354	98,640
Financial instruments	0	0
Cash collateral received	0	0
Net amount	126,354	98,640
Interest Rate Lock Commitments [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	2,317	4,859
Financial instruments	0	0
Cash collateral received	0	0
Net amount	2,317	4,859
Deutsche Bank Securities LLC [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	9,415	3,748
Financial instruments	0	0
Cash collateral received	0	0
Net amount	9,415	3,748
Citigroup Global Markets Inc. [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	2,116	429
Financial instruments	0	0
Cash collateral received	0	0
Net amount	2,116	429
Wells Fargo Securities, LLC [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	950	146
Financial instruments	0	0
Cash collateral received	0	0
Net amount	950	146
J.P. Morgan Securities LLC [member]
Offsetting Assets [Line Items]
Total derivative assets after netting	637	2,020
Financial instruments	0	0
Cash collateral received	0	0
Net amount	637	2,020
Bank of America, N.A. [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	627	0
Financial instruments	0	0
Cash collateral received	0	0
Net amount	627	0
Goldman Sachs [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	558	0
Financial instruments	0	0
Cash collateral received	0	0
Net amount	558	0
RJ O'Brien & Associates, LLC [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	141	656
Financial instruments	0	0
Cash collateral received	0	0
Net amount	141	656
Federal National Mortgage Association [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	9	1,606
Financial instruments	0	0
Cash collateral received	0	0
Net amount	9	1,606
Credit Suisse Securities (USA) LLC [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	0	809
Financial instruments	0	0
Cash collateral received	0	0
Net amount	0	809
Morgan Stanley & Co. LLC [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	0	457
Financial instruments	0	0
Cash collateral received	0	0
Net amount	0	457
Other [Member]
Offsetting Assets [Line Items]
Total derivative assets after netting	453	511
Financial instruments	0	0
Cash collateral received	0	0
Net amount	$ 453	$ 511

Derivative Activities - Schedul

Derivative Activities - Schedule of Offsetting of Derivative Liabilities and Financial Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	$ 4,411,601	$ 3,184,191
Gross amounts offset in the consolidated balance sheet	(5,221)	(1,999)
Net amounts of liabilities presented in the consolidated balance sheet	4,406,380	3,182,192
Unpaid Principal Balance [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	4,394,597	3,182,504
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	4,394,597	3,182,504
Interest Rate Lock Commitments [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	3,418	227
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	3,418	227
Forward Purchase Contracts [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	11,964	248
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	11,964	248
Forward Sales Contracts [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	1,719	2,830
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	1,719	2,830
Derivatives Not Subject To Master Netting Adjustment [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	3,418	227
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	3,418	227
Netting [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	0	0
Gross amounts offset in the consolidated balance sheet	(5,221)	(1,999)
Net amounts of liabilities presented in the consolidated balance sheet	(5,221)	(1,999)
Derivatives Subject to Master Netting Arrangements [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	13,683	3,078
Gross amounts offset in the consolidated balance sheet	(5,221)	(1,999)
Net amounts of liabilities presented in the consolidated balance sheet	8,462	1,079
Derivative Liabilities Before Netting [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	17,101	3,305
Gross amounts offset in the consolidated balance sheet	(5,221)	(1,999)
Net amounts of liabilities presented in the consolidated balance sheet	11,880	1,306
Unamortized Debt Issuance Costs [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	(97)	(1,618)
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	(97)	(1,618)
Security Sold Under Agreements to Repurchase [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	4,394,500	3,180,886
Gross amounts offset in the consolidated balance sheet	0	0
Net amounts of liabilities presented in the consolidated balance sheet	$ 4,394,500	$ 3,180,886

Derivative Activities - Summa_4

Derivative Activities - Summary of Derivative Liabilities, Financial Liabilities and Collateral Pledged by Counterparty (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	$ 4,406,380	$ 3,182,192
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(4,394,500)	(3,180,886)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	11,880	1,306
Interest Rate Lock Commitments [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	3,418	227
Gross amounts not offset in the consolidated balance sheet, Financial instruments	0	0
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	3,418	227
Bank of America, N.A. [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	1,424,559	839,057
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(1,424,559)	(838,771)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	286
Credit Suisse Securities (USA) LLC [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	683,565	845,567
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(683,339)	(845,567)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	226	0
Deutsche Bank Securities LLC [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	701,294	374,526
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(701,294)	(374,526)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	0
J.P. Morgan Securities LLC [member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	448,773	373,186
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(448,773)	(373,186)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	0
Mizuho Securities [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	276,791	0
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(276,791)	0
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	0
Daiwa Capital Markets [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	262,985	153,833
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(262,940)	(153,730)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	45	103
Morgan Stanley & Co. LLC [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	224,035	164,530
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(223,627)	(164,530)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	408	0
Citigroup Global Markets Inc. [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	118,762	235,541
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(116,091)	(235,319)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	2,671	222
RBC Capital Markets, L.P. [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	95,027	92,014
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(95,027)	(91,805)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	209
BNP Paribas [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	91,062	45,411
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(91,062)	(45,411)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	0
Wells Fargo Securities, LLC [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	71,094	50,360
Gross amounts not offset in the consolidated balance sheet, Financial instruments	(71,094)	(50,360)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	0	0
Federal National Mortgage Association [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	4,350	0
Gross amounts not offset in the consolidated balance sheet, Financial instruments	0	0
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	4,350	0
Barclays Capital Inc. [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	270	9,374
Gross amounts not offset in the consolidated balance sheet, Financial instruments	0	(9,299)
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	270	75
Other [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	492	184
Gross amounts not offset in the consolidated balance sheet, Financial instruments	0	0
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	492	184
Unamortized Debt Issuance Costs [Member]
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the consolidated balance sheet	(97)	(1,618)
Gross amounts not offset in the consolidated balance sheet, Financial instruments	97	1,618
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	0	0
Net amount	$ 0	$ 0

Derivative Activities - Net Gai

Derivative Activities - Net Gains (Losses) Recognized on Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gain Loss on mortgage loans acquired for sale [Member] | Interest Rate Lock Commitments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	$ (7,700)	$ 24,694	$ (26,431)	$ 70,131
Interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	(37)	0	(118)	0
Fixed-rate assets and LIBOR- indexed repurchase agreements [Member] | Net gain (loss) on investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	691	(5,910)	1,029	(14,943)
CRT Agreements [Member] | Net gain (loss) on investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	30,552	14,960	92,621	68,863
Interest rate lock commitments and mortgage loans acquired for sale at fair value [Member] | Gain Loss on mortgage loans acquired for sale [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	15,584	(16,943)	56,818	(32,308)
Mortgage service rights [Member] | Net loan servicing fees [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains on derivative financial instruments used as economic hedges	$ (12,093)	$ 4,576	$ (44,378)	$ (1,731)

Real Estate Acquired in Settl_3

Real Estate Acquired in Settlement of Loans - Summary of Financial Information Relating to REO (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Real Estate [Abstract]
Balance at beginning of period	$ 109,271	$ 207,034	$ 162,865	$ 274,069
Transfer from mortgage loans at fair value and advances	7,508	22,951	26,229	76,981
Transfer to real estate held for investment	(559)	(2,555)	(4,123)	(14,300)
Transfer from real estate held for investment	655	0	1,112	0
Results of REO:
Valuation adjustments, net	(3,323)	(6,423)	(13,990)	(21,749)
Gain on sale, net	3,013	3,280	8,157	10,895
Total gain (loss), net	(310)	(3,143)	(5,833)	(10,854)
Sales	(20,960)	(39,253)	(84,645)	(140,862)
Balance at end of period	95,605	$ 185,034	95,605	$ 185,034
REO pledged to secure assets sold under agreements to repurchase	43,970		43,970		$ 76,037
REO held in a consolidated subsidiary whose stock is pledged to secure financings of such properties	25,429		25,429		48,495
Real estate pledged to creditors	$ 69,399		$ 69,399		$ 124,532

Mortgage Servicing Rights - Sum

Mortgage Servicing Rights - Summary of MSRs Carried at Fair Value (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Servicing Asset At Fair Value Changes In Fair Value [Abstract]
Balance at beginning of period		$ 1,010,507	$ 77,624	$ 91,459	$ 64,136
Transfer of mortgage servicing rights from mortgage servicing rights carried at lower of amortized cost or fair value pursuant to a change in accounting principle		0	0	773,035	0
Balance after reclassification		1,010,507	77,624	864,494	64,136
Purchases		0	10	0	79
Sales		(100)	0	(100)	0
MSRs resulting from mortgage loan sales		96,383	8,655	228,337	28,467
Due to changes in valuation inputs used in valuation model	[1]	33,004	(2,628)	101,699	(6,956)
Other changes in fair value	[2]	(30,053)	(1,349)	(84,689)	(3,414)
Change in fair value, Total		2,951	(3,977)	17,010	(10,370)
Balance at end of period		1,109,741	$ 82,312	1,109,741	$ 82,312
Fair value of mortgage servicing rights pledged to secure Assets sold under agreements to repurchase and Notes payable (3)	[3]	$ 1,090,406		$ 1,090,406		$ 90,284
[1]	Principally reflects changes in pricing spread (discount rate) and prepayment speed inputs, primarily due to changes in market interest rates.
[2]	Represents changes due to realization of expected cash flows.
[3]	During 2018, beneficial interests in Fannie Mae MSRs are pledged as collateral for both Assets sold under agreements to repurchase and Notes payable as discussed in Note 17 – Notes Payable.

Mortgage Servicing Rights - S_2

Mortgage Servicing Rights - Summary of MSRs Carried at Lower of Amortized Cost or Fair Value (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	$ 673,433	$ 772,870	$ 606,103
Transfer of mortgage servicing right to mortgage servicing rights carried at fair value pursuant to a change in accounting principle	0	(772,870)	0
Balance after reclassification	673,433	0	606,103
MSRs resulting from mortgage loan sales	74,183	0	178,894
Amortization	(21,634)	0	(59,015)
Balance at end of period	725,982	0	725,982
Balance at beginning of period	(16,257)	(19,548)	(13,672)
Reduction resulting from change in accounting principle	0	19,548	0
Balance after reclassification	(16,257)	0	(13,672)
Additions to valuation allowance	(1,702)	0	(4,287)
Balance at end of period	(17,959)	0	(17,959)
MSRs, net	708,023	$ 0	708,023	$ 753,322
Fair value at beginning of period	682,437		626,334
Fair value at end of period	$ 728,828		$ 728,828
Assets sold under agreements to repurchase				584,762
Notes payable				156,846
Total				$ 741,608

Mortgage Servicing Rights - S_3

Mortgage Servicing Rights - Summary of Net Mortgage Loan Servicing Fees Relating to MSRs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Transfers And Servicing [Abstract]
Contractually-specified servicing fees	$ 49,864	$ 42,237	$ 147,262	$ 119,223
Late charges	252	173	685	536
Other	2,859	1,870	5,988	4,110
Net mortgage loan servicing fees	$ 52,975	$ 44,280	$ 153,935	$ 123,869

Assets Sold Under Agreements _3

Assets Sold Under Agreements to Repurchase - Summary of Financial Information Relating to Assets Sold under Agreements to Repurchase (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Weighted-average interest rate	3.19%	2.72%	3.12%	2.57%
Average balance	$ 4,072,301,000	$ 3,474,903,000	$ 3,573,805,000	$ 3,388,626,000
Total interest expense	29,725,000	26,157,000	79,705,000	72,280,000
Maximum daily amount outstanding	5,091,893,000	$ 3,973,869,000	5,677,797,000	$ 4,083,326,000
Unpaid principal balance	4,394,597,000		4,394,597,000		$ 3,182,504,000
Assets sold under agreements to repurchase, At year end	4,394,500,000		$ 4,394,500,000		$ 3,180,886,000
Weighted-average interest rate			3.23%		2.77%
Available borrowing capacity, Committed			$ 564,023,000		$ 749,650,000
Available borrowing capacity, Uncommitted			1,947,494,000		2,030,607,000
Available borrowing capacity			2,511,517,000		2,780,257,000
Margin deposits placed with counterparties included in Other assets	42,550,000		42,550,000		28,154,000
Real Estate Held for Investment [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	31,795,000		31,795,000		31,128,000
Assets Sold Under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Unamortized debt issuance costs and premiums, net	(97,000)		(97,000)		(1,618,000)
Mortgage-backed securities at fair value [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	2,126,507,000		2,126,507,000		989,461,000
Mortgage loans acquired for sale at fair value [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	1,898,155,000		1,898,155,000		1,201,992,000
Mortgage loans at fair value [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	332,093,000		332,093,000		760,853,000
Real estate acquired in settlement of loans [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	69,399,000		69,399,000		124,532,000
Deposits securing CRT Agreements [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	378,090,000		378,090,000		400,778,000
Derivative assets related to CRT Agreements [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	27,710,000		27,710,000		26,058,000
Mortgage service rights [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets securing agreements to repurchase	$ 1,090,406,000		$ 1,090,406,000		$ 651,575,000

Assets Sold Under Agreements _4

Assets Sold Under Agreements to Repurchase - Summary of Financial Information Relating to Assets Sold under Agreements to Repurchase (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Maturity date description			The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Master Repurchase Agreement [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Incentives as a reduction to finance mortgage loans included in interest expense	$ 5		$ 11
Maturity date description			The master repurchase agreement is subject to a rolling six month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Assets Sold Under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amortization of debt issuance premiums	$ 3.1		$ 4.8
Amortization of debt issuance costs		$ 1.9		$ 6.1

Assets Sold Under Agreements _5

Assets Sold Under Agreements to Repurchase - Summary of Maturities of Outstanding Assets Sold under Agreements to Repurchase by Facility Maturity Date (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	$ 4,394,597
Weighted average maturity (in months)	3 years 10 months 24 days
Within 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	$ 2,462,431
Over 30 to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	0
Over 90 days to 180 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	10,328
Over 180 days to 1 year [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	1,815,302
Over one year to two years [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Maturity of repurchase agreements	$ 106,536

Assets Sold Under Agreements _6

Assets Sold Under Agreements to Repurchase - Summary of Assets Sold under Agreements to Repurchase by Counterparty (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Credit Suisse First Boston Mortgage Capital LLC [Member] | CRT Agreements sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 50,793
Weighted average maturity	Oct. 10, 2018
Credit Suisse First Boston Mortgage Capital LLC [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 696,567
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Dec. 17, 2018
Facility maturity	Apr. 26, 2019
JPMorgan Chase & Co. [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 20,251
Weighted average maturity	Oct. 26, 2018
JPMorgan Chase & Co. [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 4,354
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Nov. 17, 2018
Facility maturity	Oct. 11, 2019
JPMorgan Chase & Co., Maturity in 2019 [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 100,153
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Mar. 14, 2019
Facility maturity	Mar. 14, 2019
Citibank, N.A. [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 118,546
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Dec. 13, 2018
Facility maturity	Jun. 7, 2019
Bank of America, N.A. [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 47,090
Weighted average maturity	Oct. 21, 2018
Bank of America, N.A. [Member] | CRT Agreements sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 25,475
Weighted average maturity	Oct. 19, 2018
Bank of America, N.A. [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 16,589
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Oct. 18, 2018
Facility maturity	Jul. 1, 2019
Deutsche Bank [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 33,676
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Dec. 17, 2018
Facility maturity	Mar. 31, 2019
BNP Paribas Corporate & Institutional Banking [Member] | CRT Agreements sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 17,009
Weighted average maturity	Oct. 22, 2018
BNP Paribas Corporate & Institutional Banking [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 555
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Dec. 14, 2018
Facility maturity	Aug. 2, 2019
Morgan Stanley [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 10,781
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Dec. 13, 2018
Facility maturity	Aug. 23, 2019
Royal Bank of Canada [Member] | Mortgage loans, REO and MSRs sold under agreements to repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 4,454
Mortgage acquired for sale Weighted-average repurchase agreement maturity	Jan. 13, 2019
Facility maturity	Apr. 16, 2019
Daiwa Capital Markets [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 16,385
Weighted average maturity	Oct. 19, 2018
Mizuho Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 8,634
Weighted average maturity	Oct. 10, 2018
Wells Fargo, N.A. [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Amount at risk	$ 4,034
Weighted average maturity	Oct. 16, 2018

Mortgage Loan Participation P_3

Mortgage Loan Participation Purchase and Sale Agreements - Summary of Mortgage Loan Participation Purchase and Sale Agreements (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
At period end:
Mortgage loan participation purchase and sale agreements, At year end	$ 31,578,000		$ 31,578,000		$ 44,488,000
Mortgage Loan Participation Purchase and Sale Agreement [Member]
Mortgage Loan Participation Purchase And Sale Agreement [Line Items]
Weighted-average interest rate	3.39%	2.48%	3.21%	2.28%
Average balance	$ 78,806,000	$ 59,701,000	$ 51,687,000	$ 65,290,000
Total interest expense	739,000	409,000	1,396,000	1,225,000
Maximum daily amount outstanding	258,983,000	$ 99,441,000	258,983,000	$ 99,441,000
At period end:
Amount outstanding	31,675,000		31,675,000		44,550,000
Unamortized debt issuance costs	(97,000)		(97,000)		(62,000)
Mortgage loan participation purchase and sale agreements, At year end	31,578,000		$ 31,578,000		$ 44,488,000
Weighted-average interest rate			3.61%		2.82%
Mortgage loans acquired for sale pledged to secure mortgage loan participation purchase and sale agreements	$ 32,392,000		$ 32,392,000		$ 47,285,000

Mortgage Loan Participation P_4

Mortgage Loan Participation Purchase and Sale Agreements - Summary of Mortgage Loan Participation Purchase and Sale Agreements (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Mortgage Loan Participation Purchase And Sale Agreement [Line Items]
Amortization of debt issuance (premiums) and costs, net			$ (3,193)	$ 10,243
Mortgage Loan Participation Purchase and Sale Agreement [Member]
Mortgage Loan Participation Purchase And Sale Agreement [Line Items]
Amortization of debt issuance (premiums) and costs, net	$ 65,000	$ 31,000	$ 141,000	$ 94,000

Exchangeable Senior Notes - Add

Exchangeable Senior Notes - Additional Information (Detail) - Exchangeable Senior Notes due May 1, 2020 [Member]	Apr. 30, 2013USD ($)	Sep. 30, 2018USD ($)$ / shares
Debt Instrument [Line Items]
Issuance of debt through private offering	$ 250,000,000
Percentage of interest on debt	5.375%
Number of shares exchanged per exchangeable notes		33.8667
Principal amount of the exchangeable notes		$ 1,000
Increased in cash dividend | $ / shares		$ 0.57
Maturity date of debt instrument		May 1, 2020
Initial Exchangeable Rate [Member]
Debt Instrument [Line Items]
Number of shares exchanged per exchangeable notes	33.5149

Exchangeable Senior Notes - Sum

Exchangeable Senior Notes - Summary of Financial Information Relating to Exchangeable Senior Notes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Average balance	$ 250,000	$ 250,000	$ 250,000	$ 250,000
Carrying value:
UPB	250,000		250,000		$ 250,000
Exchangeable senior notes	248,053		248,053		247,186
Convertible Debt [Member]
Debt Instrument [Line Items]
Total interest expense	3,652	$ 3,636	10,945	$ 10,895
Carrying value:
Unamortized debt issuance costs	$ (1,947)		$ (1,947)		$ (2,814)

Notes Payable - Additional Info

Notes Payable - Additional Information (Detail) - USD ($)	Apr. 25, 2018	Sep. 30, 2018	Feb. 01, 2018	Mar. 24, 2017
Secured Term Notes [Member]
Short-term Debt [Line Items]
Aggregate loan amount	$ 450,000,000
Debt instrument payable start date	2018-05
Maturity date of debt instrument	Apr. 25, 2023
Debt instrument extended maturity date subject to term note indenture	Apr. 25, 2025
Secured Term Notes [Member] | Fixed-rate assets and LIBOR- indexed repurchase agreements [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis	one-month
Debt instrument interest rate spread	2.35%
Loan and Security Agreement with Credit Suisse First Boston Mortgage Capital LLC [Member]
Short-term Debt [Line Items]
Maturity date of debt instrument		Feb. 1, 2020
Loan and Security Agreement with Credit Suisse First Boston Mortgage Capital LLC [Member] | Maximum [Member]
Short-term Debt [Line Items]
Aggregate loan amount			$ 175,000,000
Amended and Restated Loan and Security Agreement with Citibank, N.A. [Member]
Short-term Debt [Line Items]
Redemption and termination period of debt instrument		2017-12
Amended and Restated Loan and Security Agreement with Citibank, N.A. [Member] | Maximum [Member]
Short-term Debt [Line Items]
Aggregate loan amount				$ 400,000,000
Loan and Security Agreement with Barclays Bank PLC [Member]
Short-term Debt [Line Items]
Maturity date of debt instrument		Feb. 1, 2018
Loan and Security Agreement with Barclays Bank PLC [Member] | Maximum [Member]
Short-term Debt [Line Items]
Aggregate loan amount				$ 170,000,000

Notes Payable - Summary of Fina

Notes Payable - Summary of Financial Information Relating to Note Payable (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Weighted-average interest rate	4.53%	6.30%	4.58%	5.57%
Average balance	$ 445,149,000	$ 79,345,000	$ 251,052,000	$ 152,395,000
Total interest expense	5,351,000	2,320,000	9,032,000	9,719,000
Carrying value:
Amount outstanding	450,000,000		450,000,000
Balance	$ 445,318,000		445,318,000		$ 0
Weighted-average interest rate	4.44%
MSRs pledged to secure notes payable	$ 1,090,406,000		1,090,406,000		180,317,000
Notes payable [Member]
Debt Instrument [Line Items]
Maximum daily amount outstanding	445,318,000	$ 160,106,000	445,318,000	$ 275,106,000
Carrying value:
Unamortized debt issuance costs	$ (4,682,000)		$ (4,682,000)		$ 0

Notes Payable - Summary of Fi_2

Notes Payable - Summary of Financial Information Relating to Note Payable (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Amortization of debt issuance (premiums) and costs, net			$ (3,193,000)	$ 10,243,000
Notes payable [Member]
Debt Instrument [Line Items]
Amortization of debt issuance (premiums) and costs, net	$ 255,000	$ 1,000,000	$ 426,000	$ 3,300,000

Asset-Backed Financing of a V_3

Asset-Backed Financing of a Variable Interest Entity at Fair Value - Summary of Financial Information Relating to Asset-Backed Financing of a VIE (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Asset-backed financing of a variable interest entity at fair value	$ 278,113		$ 278,113		$ 307,419
Variable Interest Entities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Asset-backed financing of a variable interest entity at fair value	278,113		278,113		307,419
Asset-Backed Financing of the VIE at Fair Value [Member] | Variable Interest Entities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Weighted-average fair value	285,284	$ 325,763	292,770	$ 337,073
Total interest expense	$ 2,740	$ 3,515	$ 7,836	$ 10,520
Weighted-average interest rate	3.52%	3.34%	3.51%	3.41%
Asset-backed financing of a variable interest entity at fair value	$ 278,113		$ 278,113		307,419
UPB	$ 287,086		$ 287,086		$ 316,684
Weighted-average interest rate			3.51%		3.51%

Liability for Losses under Re_3

Liability for Losses under Representations and Warranties - Summary of Company's Liability for Losses under Representations and Warranties (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Mortgage Banking [Abstract]
Balance, beginning of period	$ 7,625	$ 10,697	$ 8,678	$ 15,350
Provision for losses:
Pursuant to mortgage loan sales	636	1,075	1,724	2,355
Reduction in liability due to change in estimate	(848)	(1,642)	(3,030)	(7,523)
(Losses incurred) recoveries, net	0	(83)	41	(135)
Balance, end of period	7,413	10,047	7,413	10,047
UPB of mortgage loans subject to representations and warranties at end of period	$ 83,370,583	$ 67,196,537	$ 83,370,583	$ 67,196,537

Commitments and Contingencies -

Commitments and Contingencies - Company's Outstanding Contractual Commitments (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Commitments to purchase mortgage loans:
Commitments to purchase mortgage loans acquired for sale	$ 1,682,007
Commitments to fund Deposits securing CRT agreements	578,508
Firm commitment to purchase credit risk transfer security	$ 294,698

Shareholders' Equity - Summary

Shareholders' Equity - Summary of Preferred Shares of Benefical Interest (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Number of shares	12,400,000	12,400,000
Liquidation preference	$ 310,000,000	$ 310,000,000
Issuance discount	10,293,000
Carrying value	$ 299,707,000	$ 299,707,000
8.125% Series A Preferred Stock [Member]
Class Of Stock [Line Items]
Number of shares	4,600,000
Liquidation preference	$ 115,000,000
Issuance discount	3,828,000
Carrying value	$ 111,172,000
8.00% Series B Preferred Stock [Member]
Class Of Stock [Line Items]
Number of shares	7,800,000
Liquidation preference	$ 195,000,000
Issuance discount	6,465,000
Carrying value	$ 188,535,000

Shareholders' Equity - Summar_2

Shareholders' Equity - Summary of Preferred Shares of Benefical Interest (Parenthetical) (Detail) - $ / shares	Jul. 05, 2017	Jul. 31, 2017	Mar. 31, 2017	Sep. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Preferred stock, par value				$ 0.01	$ 0.01
8.125% Series A Preferred Stock [Member]
Class Of Stock [Line Items]
Cumulative dividend, beneficial interest rate			8.125%	8.125%
Sale of Stock, Transaction Date				Mar. 31, 2017
Preferred stock, par value			$ 0.01	$ 0.01
8.00% Series B Preferred Stock [Member]
Class Of Stock [Line Items]
Cumulative dividend, beneficial interest rate	8.00%	5.99%		8.00%
Sale of Stock, Transaction Date				Jul. 31, 2017
Preferred stock, par value		$ 0.01		$ 0.01

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($)	Jul. 05, 2017	Jul. 31, 2017	Mar. 31, 2017	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Aug. 31, 2015
Schedule Of Capitalization Equity [Line Items]
Preferred stock, par value					$ 0.01		$ 0.01		$ 0.01
Reimbursement agreement effective date							Feb. 1, 2013
Reimbursement paid for every $100 of performance incentive fees earned							$ 10
Performance incentive fees earned							100
Performance incentive fees, incurred					$ 683,000		683,000
Payments of contingent underwriting fees to underwriters					0	$ 61,000	0	$ 61,000
Initial Public Offering [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement paid for every $100 of performance incentive fees earned							20
Performance incentive fees earned							$ 100
Reimbursement agreement expiry date							Feb. 1, 2019
Management [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement of contingent underwriting fee to manager					0	30,000	$ 0	30,000
PNMAC Capital Management LLC [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement of contingent underwriting fee to manager						$ 30,000		$ 30,000
Maximum [Member]
Schedule Of Capitalization Equity [Line Items]
Common stock shares Repurchase authorized amount										$ 300,000,000
Reimbursement payable in a 12-month period							1,000,000
Underwriting cost paid							2,900,000
Maximum [Member] | Initial Public Offering [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement payable in a 12-month period							2,000,000
Amount paid by underwriters					$ 5,900,000		$ 5,900,000
Scenario Forecast [Member] | Underwriter [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement of performance incentive fees				$ 137,000
Scenario Forecast [Member] | PNMAC Capital Management LLC [Member]
Schedule Of Capitalization Equity [Line Items]
Reimbursement of performance incentive fees				$ 68,000
8.125% Series A Preferred Stock [Member]
Schedule Of Capitalization Equity [Line Items]
Issuance of preferred shares, Shares			4.6
Cumulative dividend, beneficial interest rate			8.125%				8.125%
Preferred stock, par value			$ 0.01		$ 0.01		$ 0.01
Preferred stock, dividends per share paid							$ 1.52
Statutory Dividend Payment Restrictions Disclosure							The Company pays quarterly cumulative dividends on its Preferred Shares on the 15th day of each March, June, September and December, provided that if any dividend payment date is not a business day, then the dividend that would otherwise be payable on that dividend payment date may be paid on the following business day.
8.125% Series A Preferred Stock [Member] | Fixed Annuity | Date Of Original Issuance To March 14,2024 [Member]
Schedule Of Capitalization Equity [Line Items]
Preferred stock, liquidation preference			$ 25
8.125% Series A Preferred Stock [Member] | Floating Rate [Member] | March 15,2024 and Thereafter [member]
Schedule Of Capitalization Equity [Line Items]
Cumulative dividend, beneficial interest rate			5.831%
8.00% Series B Preferred Stock [Member]
Schedule Of Capitalization Equity [Line Items]
Issuance of preferred shares, Shares		7,800,000
Cumulative dividend, beneficial interest rate	8.00%	5.99%					8.00%
Preferred stock, par value		$ 0.01			0.01		$ 0.01
Preferred stock, liquidation preference		$ 25
Preferred stock, dividends per share paid							1.50
8.125% Series A And 8.00% Series B Preferred Stock [Member]
Schedule Of Capitalization Equity [Line Items]
Preferred stock redemption price per share					$ 25		$ 25

Shareholders' Equity - Summar_3

Shareholders' Equity - Summary of Share Repurchase Activity (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity [Abstract]
Common shares repurchased	0	966	671	1,105
Cumulative shares repurchased	14,731		14,731
Cost of common shares repurchased	$ 0	$ 16,417	$ 10,719	$ 18,724
Cumulative cost of shares repurchased	$ 216,625		$ 216,625

Net Mortgage Loan Servicing F_3

Net Mortgage Loan Servicing Fees - Summary of Net Loan Servicing Fees (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Components of Net Servicing Fee Income [Line Items]
Servicing fees		$ 52,975	$ 44,280	$ 153,935	$ 123,869
Effect of MSRs:
Realization of cashflows	[1]	33,004	(2,628)	101,699	(6,956)
Other	[2]	(30,053)	(1,349)	(84,689)	(3,414)
Change in fair value, Total		2,951	(3,977)	17,010	(10,370)
Amortization			(21,634)	0	(59,015)
Additions to impairment valuation allowance			(1,702)	0	(4,287)
Total Effect of MSRs				(27,368)	(75,403)
Net mortgage loan servicing fees		44,394	21,876	128,135	49,325
Average servicing portfolio		81,350,980	63,584,416	77,522,709	61,764,228
PennyMac Financial Services, Inc. [Member]
Effect of MSRs:
Net mortgage loan servicing fees		561	333	1,568	859
From PFSI—MSR recapture income		561	333	1,568	859
Nonaffiliates [Member]
Components of Net Servicing Fee Income [Line Items]
Servicing fees		49,864	42,237	147,262	119,223
Ancillary and other fees		3,111	2,043	6,673	4,646
Effect of MSRs:
Realization of cashflows		(30,053)	(2,628)	(84,689)	(6,956)
Other		33,127	(1,349)	101,822	(3,414)
Change in fair value, Total		3,074	(3,977)	17,133	(10,370)
Loss on sale		(123)	0	(123)	0
Amortization		0	(21,634)	0	(59,015)
Additions to impairment valuation allowance		0	(1,702)	0	(4,287)
Total Effect of MSRs		(9,142)	(22,737)	(27,368)	(75,403)
Net mortgage loan servicing fees		43,833	21,543	126,567	48,466
Nonaffiliates [Member] | Mortgage service rights [Member]
Effect of MSRs:
(Losses) gains on hedging derivatives		$ (12,093)	$ 4,576	$ (44,378)	$ (1,731)
[1]	Principally reflects changes in pricing spread (discount rate) and prepayment speed inputs, primarily due to changes in market interest rates.
[2]	Represents changes due to realization of expected cash flows.

Net Gain on Mortgage Loans Ac_3

Net Gain on Mortgage Loans Acquired for Sale - Summary of Net Gain on Mortgage Loans Acquired for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Non cash gain:
Receipt of MSRs in mortgage loan sale transactions			$ 228,337	$ 207,361
Provision for losses relating to representations and warranties provided in mortgage loan sales:
Pursuant to mortgage loans sales	$ (636)	$ (1,075)	(1,724)	(2,355)
Reduction in liability due to change in estimate	(848)	(1,642)	(3,030)	(7,523)
Change in fair value of financial instruments held at end of period:
Net gain on mortgage loans acquired for sale	24,810	17,967	41,579	54,284
PennyMac Financial Services, Inc. [Member]
Change in fair value of financial instruments held at end of period:
Net gain on mortgage loans acquired for sale	2,689	3,275	8,221	9,340
Nonaffiliates [Member]
Cash loss:
Mortgage loans	(104,475)	(51,485)	(272,496)	(135,666)
Hedging activities	24,659	(13,468)	63,047	(16,931)
Cash gain, net of effects of cash hedging, on sale of mortgage loans acquired for sale	(79,816)	(64,953)	(209,449)	(152,597)
Non cash gain:
Recognition of fair value of firm commitment to purchase credit risk transfer security	12,311	0	16,737	0
Receipt of MSRs in mortgage loan sale transactions	96,383	82,838	228,337	207,361
Provision for losses relating to representations and warranties provided in mortgage loan sales:
Pursuant to mortgage loans sales	(636)	(1,075)	(1,724)	(2,355)
Reduction in liability due to change in estimate	848	1,642	3,030	7,523
Provision for losses relating to representations and warranties	212	567	1,306	5,168
Change in fair value of financial instruments held at end of period:
IRLCs	(3,907)	880	(5,733)	(2,502)
Mortgage loans	6,013	(1,165)	8,389	2,891
Hedging derivatives	(9,075)	(3,475)	(6,229)	(15,377)
Total non cash portion of gain on mortgage loans acquired for sale	(6,969)	(3,760)	(3,573)	(14,988)
Net gain on mortgage loans acquired for sale	$ 22,121	$ 14,692	$ 33,358	$ 44,944

Net Gain (Loss) on Investment_2

Net Gain (Loss) on Investments - Summary of Net Gain (Loss) on Investments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gain (loss) on investments	$ 9,683	$ 13,834	$ 35,210	$ 58,147
Nonaffiliates [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Mortgage-backed securities at fair value	(19,030)	5,001	(50,288)	9,168
CRT Agreements	29,481	15,151	90,528	66,591
Asset-backed financing of a VIE at fair value	3,516	(2,158)	12,658	(5,581)
Hedging derivatives	691	(5,910)	1,029	(14,943)
Net gain (loss) on investments	7,977	17,499	24,233	69,067
PennyMac Financial Services, Inc. [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gain (loss) on investments	1,706	(3,665)	10,977	(10,920)
Variable Interest Entities [Member] | Nonaffiliates [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Mortgage loans at fair value	(3,630)	2,138	(11,992)	6,309
Distressed mortgage loans [Member] | Nonaffiliates [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Mortgage loans at fair value	$ (3,051)	$ 3,277	$ (17,702)	$ 7,523

Net Interest Income - Summary o

Net Interest Income - Summary of Net Interest Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
ESS	$ 62,324	$ 51,577	$ 155,648	$ 152,063
Interest expense:
Total interest expense	29,725	26,157	79,705	72,280
Notes payable	5,351	2,320	9,032	9,719
Interest expense, total	46,609	40,277	121,490	115,882
Net interest income	15,715	11,300	34,158	36,181
Convertible Debt [Member]
Interest expense:
Total interest expense	3,652	3,636	10,945	10,895
PennyMac Financial Services, Inc. [Member]
Interest income:
ESS	3,740	3,998	11,584	13,011
Interest expense:
Total interest expense	1,812	2,116	5,686	5,946
Nonaffiliates [Member]
Interest income:
Short-term investments	385	132	656	516
Mortgage-backed securities	15,903	7,447	37,127	21,954
Mortgage loans acquired for sale at fair value	22,591	16,202	51,874	40,699
Distressed	5,245	14,213	18,086	53,456
Deposits securing CRT Agreements	3,190	1,440	8,788	2,703
Placement fees relating to custodial funds	7,979	4,330	18,218	8,212
Other	225	49	478	142
ESS	58,584	47,579	144,064	139,052
Interest expense:
Total interest expense	29,725	26,157	79,705	72,280
Mortgage loan participation purchase and sale agreements	739	409	1,396	1,225
Notes payable	5,351	2,320	9,032	9,719
Asset-backed financings of a VIE at fair value	2,740	3,515	7,836	10,520
Interest shortfall on repayments of mortgage loans serviced for Agency securitizations	1,897	1,638	5,294	4,068
Interest on mortgage loan impound deposits	693	486	1,596	1,229
Interest expense, total	44,797	38,161	115,804	109,936
Nonaffiliates [Member] | Convertible Debt [Member]
Interest expense:
Total interest expense	3,652	3,636	10,945	10,895
Nonaffiliates [Member] | Variable Interest Entities [Member]
Interest income:
Mortgage loans at fair value	$ 3,066	$ 3,766	$ 8,837	$ 11,370

Net Interest Income - Summary_2

Net Interest Income - Summary of Net Interest Income (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Maturity date description		The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Master Repurchase Agreement [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Incentives as a reduction to finance mortgage loans included in interest expense	$ 5	$ 11
Maturity date description		The master repurchase agreement is subject to a rolling six month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity

Share-Based Compensation Plan_2

Share-Based Compensation Plans - Summary of Share-Based Compensation Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share units granted	0	2	245	262
Total fair value of share units granted	$ 0	$ 36	$ 3,823	$ 3,992
Total share units vested	1	0	289	284
Total share units forfeited	2	0	2	13
Compensation expense relating to share-based grants	$ 1,566	$ 737	$ 4,322	$ 3,864
Restricted Shares Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share units granted	0	2	129	136
Total fair value of share units granted	$ 0	$ 36	$ 2,281	$ 2,317
Total share units vested	1	0	261	284
Total share units forfeited	2	0	2	13
Performance Shares Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share units granted	0	0	116	126
Total fair value of share units granted	$ 0	$ 0	$ 1,542	$ 1,675
Total share units vested	0	0	28	0
Total share units forfeited	0	0	0	0

Other Expenses - Summary of Oth

Other Expenses - Summary of Other Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Non operating Income Expense [Line Items]
Total other expenses	$ 2,894	$ 3,301	$ 7,758	$ 10,704
Common Overhead Allocation from PFSI [Member]
Other Non operating Income Expense [Line Items]
Total other expenses	1,210	1,193	3,387	4,220
Technology [Member]
Other Non operating Income Expense [Line Items]
Total other expenses	291	374	1,014	1,088
Insurance [Member]
Other Non operating Income Expense [Line Items]
Total other expenses	274	300	915	968
Other [Member]
Other Non operating Income Expense [Line Items]
Total other expenses	$ 1,119	$ 1,434	$ 2,442	$ 4,428

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax [Line Items]
Effective income tax rate	9.90%		15.60%
Expense (benefit) from income taxes	$ 5,100,000	$ 4,771,000	$ 20,613,000	$ 1,688,000
Income (loss) before benefit from income taxes	51,662,000	24,166,000	131,786,000	78,599,000
Percentage of deduction from taxable income					20.00%
Taxable REIT Subsidiary [Member]
Income Tax [Line Items]
Expense (benefit) from income taxes	4,800,000	4,800,000	19,900,000	(900,000)
Income (loss) before benefit from income taxes	$ 17,700,000	$ 12,000,000	$ 73,200,000	$ (4,500,000)

Earnings Per Share - Summary of

Earnings Per Share - Summary of Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 46,562	$ 19,395	$ 111,173	$ 76,911
Dividends on preferred shares	(6,235)	(6,125)	(18,703)	(9,032)
Effect of participating securities—share-based compensation awards	(236)	(231)	(541)	(760)
Net income attributable to common shareholders	40,091	13,039	91,929	67,119
Net income attributable to common shareholders	40,091	13,039	91,929	67,119
Interest on Exchangeable Notes, net of income taxes	2,661	0	7,973	6,564
Diluted net income attributable to common shareholders	$ 42,752	$ 13,039	$ 99,902	$ 73,683
Weighted-average basic shares outstanding	60,950	66,636	60,880	66,702
Dilutive securities:
Shares issuable pursuant to exchange of the Exchangeable Notes	8,467	0	8,467	8,467
Diluted weighted-average number of shares outstanding	69,417	66,636	69,347	75,169
Basic earnings per share	$ 0.66	$ 0.20	$ 1.51	$ 1.01
Diluted earnings per share	$ 0.62	$ 0.20	$ 1.44	$ 0.98

Earnings Per Share - Summary _2

Earnings Per Share - Summary of Potentially Dilutive Shares Excluded from Computation of Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Plan [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive stock excluded from the diluted earnings per share	361	643	403	699
Exchangeable Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive stock excluded from the diluted earnings per share	0	8,467	0	0

Segments - Additional Informati

Segments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018Segment
Segment Reporting [Abstract]
Number of business segments	4

Segments - Financial Highlights

Segments - Financial Highlights by Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Net investment income:
Net mortgage loan servicing fees	$ 44,394	$ 21,876	$ 128,135	$ 49,325
Net gain on mortgage loans acquired for sale	24,810	17,967	41,579	54,284
Net gain (loss) on investments	9,683	13,834	35,210	58,147
Net interest income (expense):
Interest income	62,324	51,577	155,648	152,063
Interest expense	(46,609)	(40,277)	(121,490)	(115,882)
Net interest income	15,715	11,300	34,158	36,181
Other income (loss)	13,899	10,827	28,083	26,300
Net investment income	108,501	75,804	267,165	224,237
Expenses:
Mortgage loan fulfillment and servicing fees payable to PFSI	36,327	34,909	83,280	93,171
Management fees	6,482	6,038	17,906	16,684
Other	14,030	10,691	34,193	35,783
Total expenses	56,839	51,638	135,379	145,638
Pre-tax income (loss)	51,662	24,166	131,786	78,599
Total assets at end of quarter	7,267,578	5,785,043	7,267,578	5,785,043	$ 5,604,933
Correspondent production [Member]
Net investment income:
Net mortgage loan servicing fees	0	0	0	0
Net gain on mortgage loans acquired for sale	12,496	17,963	24,810	54,117
Net gain (loss) on investments	0	0	0	0
Net interest income (expense):
Interest income	22,465	16,018	51,456	40,194
Interest expense	(12,708)	(11,351)	(30,039)	(28,214)
Net interest income	9,757	4,667	21,417	11,980
Other income (loss)	12,442	11,762	28,410	30,576
Net investment income	34,695	34,392	74,637	96,673
Expenses:
Mortgage loan fulfillment and servicing fees payable to PFSI	26,256	23,508	52,759	61,191
Management fees	0	0	0	0
Other	2,485	2,574	4,778	6,614
Total expenses	28,741	26,082	57,537	67,805
Pre-tax income (loss)	5,954	8,310	17,100	28,868
Total assets at end of quarter	1,976,188	1,304,647	1,976,188	1,304,647
Credit Sensitive Strategies [Member]
Net investment income:
Net mortgage loan servicing fees	5	47	29	91
Net gain on mortgage loans acquired for sale	12,314	4	16,769	167
Net gain (loss) on investments	26,293	18,562	72,744	74,695
Net interest income (expense):
Interest income	8,675	15,951	27,634	57,011
Interest expense	(8,792)	(13,096)	(28,899)	(41,178)
Net interest income	(117)	2,855	(1,265)	15,833
Other income (loss)	1,457	(935)	(351)	(4,281)
Net investment income	39,952	20,533	87,926	86,505
Expenses:
Mortgage loan fulfillment and servicing fees payable to PFSI	1,271	4,273	5,529	12,143
Management fees	0	0	0	0
Other	5,619	3,194	13,077	11,419
Total expenses	6,890	7,467	18,606	23,562
Pre-tax income (loss)	33,062	13,066	69,320	62,943
Total assets at end of quarter	1,348,750	1,959,792	1,348,750	1,959,792
Interest Rate Sensitive Strategies [Member]
Net investment income:
Net mortgage loan servicing fees	44,389	21,829	128,106	49,234
Net gain on mortgage loans acquired for sale	0	0	0	0
Net gain (loss) on investments	(16,610)	(4,728)	(37,534)	(16,548)
Net interest income (expense):
Interest income	30,573	19,426	75,423	54,200
Interest expense	(25,109)	(15,830)	(62,552)	(46,490)
Net interest income	5,464	3,596	12,871	7,710
Other income (loss)	0	0	0	0
Net investment income	33,243	20,697	103,443	40,396
Expenses:
Mortgage loan fulfillment and servicing fees payable to PFSI	8,800	7,128	24,992	19,837
Management fees	0	0	0	0
Other	344	265	166	1,094
Total expenses	9,144	7,393	25,158	20,931
Pre-tax income (loss)	24,099	13,304	78,285	19,465
Total assets at end of quarter	3,822,572	2,414,477	3,822,572	2,414,477
Corporate [Member]
Net investment income:
Net mortgage loan servicing fees	0	0	0	0
Net gain on mortgage loans acquired for sale	0	0	0	0
Net gain (loss) on investments	0	0	0	0
Net interest income (expense):
Interest income	611	182	1,135	658
Interest expense	0	0	0	0
Net interest income	611	182	1,135	658
Other income (loss)	0	0	24	5
Net investment income	611	182	1,159	663
Expenses:
Mortgage loan fulfillment and servicing fees payable to PFSI	0	0	0	0
Management fees	6,482	6,038	17,906	16,684
Other	5,582	4,658	16,172	16,656
Total expenses	12,064	10,696	34,078	33,340
Pre-tax income (loss)	(11,453)	(10,514)	(32,919)	(32,677)
Total assets at end of quarter	$ 120,068	$ 106,127	$ 120,068	$ 106,127

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Summary of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Additional Cash Flow Elements And Supplemental Cash Flow Information [Abstract]
Income tax payments, net of refunds	$ 900	$ (294)
Interest payments	124,332	115,108
Cumulative effect on accumulated deficit of conversion to fair value accounting	14,361	0
Non-cash investing activities:
Transfer of mortgage loans and advances to real estate acquired in settlement of loans	26,229	76,981
Transfer of real estate acquired in settlement of mortgage loans to real estate held for investment	4,123	14,300
Transfer of real estate acquired in settlement of mortgage loans from real estate held for investment	1,112	0
Receipt of mortgage servicing rights as proceeds from sales of mortgage loans	228,337	207,361
Receipt of excess servicing spread pursuant to recapture agreement with PennyMac Financial Services, Inc.	1,983	4,160
Capitalization of servicing advances pursuant to mortgage loan modifications	4,734	17,759
Non-cash financing activities:
Recognition of financing premium arising from repurchase agreement derivatives	11,411	0
Dividends declared, not paid	$ 28,817	$ 31,655

Regulatory Capital and Liquid_3

Regulatory Capital and Liquidity Requirements - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018USD ($)
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Minimum net worth amount	$ 2,500,000
Basis point	0.25%
Unpaid Principal Balance [Member]
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Basis point	0.035%
Nonperforming mortgage loans [Member]
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Basis point	2.00%
Minimum [Member]
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Tangible net worth/ total assets ratio	6.00%

Regulatory Capital and Liquid_4

Regulatory Capital and Liquidity Requirements - Summary of Capital and Liquidity Amounts and Requirements by Agencies (Detail) - Fannie Mae and Freddie Mac [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Capital Requirements By Agencies [Line Items]
Net Worth, Actual	$ 555,214	$ 487,535
Net Worth, Required	$ 213,379	$ 182,818
Tangible Net Worth / Total Assets Ratio, Actual	11.00%	12.00%
Tangible Net Worth / Total Assets Ratio, Required	6.00%	6.00%
Liquidity, Actual	$ 100,478	$ 73,252
Liquidity, Required	$ 28,983	$ 25,245

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) $ in Millions	1 Months Ended	9 Months Ended
	Oct. 31, 2018USD ($)Agreement	Sep. 30, 2018USD ($)
Subsequent Event [Line Items]
Maturity date description		The master repurchase agreement is subject to a rolling six-month term through August 18, 2019, unless terminated earlier at the option of the lender. There can be no assurance that the lender will not terminate this agreement before its stated maturity
Credit Risk Transfer Agreements [Member] | Assets Sold Under Agreements to Repurchase [Member]
Subsequent Event [Line Items]
Securities backed by deposits securing credit risk transfer agreements		$ 578.5
Subsequent Event [Member] | Repurchase Agreement Derivatives [Member]
Subsequent Event [Line Items]
Maturity date description	All agreements to repurchase assets that matured between September 31, 2018 and the date of this Report were extended or renewed.
Subsequent Event [Member] | Distressed mortgage loans [Member]
Subsequent Event [Line Items]
Number agreements to sell | Agreement	4
Unpaid principal balance agreed to sell	$ 300
Subsequent Event [Member] | Assets Sold Under Agreements to Repurchase [Member]
Subsequent Event [Line Items]
Deposits made during agreement’s aggregation period	200.5
Advance received under asset repurchase agreement	$ 571.5