Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net income	$ 97,760	$ 64,611
Adjustments to reconcile net income to net cash provided by operating activities:
Net gain on investments	(182,847)	(25,527)
Net gain on loans acquired for sale at fair value	(55,567)	(16,769)
Change in fair value of mortgage servicing rights, net of hedging results	224,125	18,228
Accrual of interest on excess servicing spread purchased from PennyMac Financial Services, Inc.	(5,833)	(7,844)
Capitalization of interest and fees on loans at fair value	(1,928)	(4,246)
Amortization of debt issuance (premiums) and costs, net	(4,596)	(727)
Accrual of unearned discounts and amortization of premiums on mortgage-backed securities, loans at fair value, and asset-backed financing of a VIE	12,405	1,462
Results of real estate acquired in settlement of loans	(595)	5,523
Share-based compensation expense	3,032	2,756
Reversal of contingent underwriting fees	(1,134)	0
Purchase of loans acquired for sale at fair value from nonaffiliates	(37,634,892)	(29,026,386)
Purchase of loans acquired for sale at fair value from PennyMac Financial Services, Inc.	(2,218,721)	(1,427,637)
Repurchase of loans subject to representation and warranties	(5,341)	(5,603)
Sale to nonaffiliates and repayment of loans acquired for sale at fair value	20,802,011	10,556,931
Sale of loans acquired for sale to PennyMac Financial Services, Inc.	17,956,971	19,267,316
Settlement of repurchase agreement derivatives	11,567	2,495
Decrease in servicing advances	42,824	32,628
Decrease in due from PennyMac Financial Services, Inc.	2,524	14
Decrease (increase) in other assets	97,717	(29,848)
Decrease in accounts payable and accrued liabilities	(41,065)	(5,812)
Increase (decrease) in due to PennyMac Financial Services, Inc.	1,189	(7,458)
(Decrease) increase in income taxes payable	(14,653)	14,620
Net cash used in operating activities	(915,047)	(591,273)
Cash flows from investing activities
Net increase in short-term investments	(1,881)	(21,086)
Purchase of investment securities at fair value	(81,202)	(814,792)
Repayment of mortgage-backed securities at fair value	144,868	73,279
Repurchase of loans at fair value	(886)	0
Sale and repayment of loans at fair value	44,984	293,535
Repayment of excess servicing spread by PennyMac Financial Services, Inc.	21,082	24,309
Settlement of firm commitment to purchase credit risk transfer securities	31,925	0
Net settlement of derivative financial instruments	(22,103)	1,898
Sale of real estate acquired in settlement of loans	31,171	63,685
Distribution from credit risk transfer agreements	61,473	57,091
Deposit of cash securing credit risk transfer arrangements	(933,370)	(77,888)
Decrease (increase) in margin deposits	48,308	(9,524)
Net cash used in investing activities	(655,631)	(409,493)
Cash flows from financing activities
Sale of assets under agreements to repurchase	51,009,663	37,309,146
Repurchase of assets sold under agreements to repurchase	(50,421,692)	(36,710,604)
Issuance of mortgage loan participation purchase and sale agreements	2,756,486	2,402,527
Repayment of mortgage loan participation purchase and sale agreements	(2,935,212)	(2,359,327)
Issuance of notes payable	933,730	450,000
Repayment of notes payable	(7,095)	0
Repayment of asset-backed financing of a variable interest entity at fair value	(13,625)	(10,431)
Sale of assets to PennyMac Financial Services, Inc. under agreements to repurchase	0	2,293
Repurchase of assets sold to PennyMac Financial Services, Inc. under agreement to repurchase	(12,309)	(7,839)
Payment of debt issuance costs	(6,331)	(8,457)
Payment of dividends to preferred shareholders	(12,472)	(12,472)
Payment of dividends to common shareholders	(61,078)	(57,963)
Issuance of common shares	366,188	0
Payment of issuance costs related to common shares	(4,791)	0
Payment of vested share-based compensation withholdings	(2,600)	0
Payment of contingent underwriting fees payable	(353)	0
Repurchase of common shares	0	(10,719)
Net cash provided by financing activities	1,588,509	986,154
Net increase (decrease) in cash	17,831	(14,612)
Cash at beginning of period	59,845	77,647
Cash at end of period	$ 77,676	$ 63,035