CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flow from operating activities
Net income	$ 376,868	$ 306,243
Adjustments to reconcile net income to net cash used in operating activities:
Net gains on loans held for sale at fair value	(754,341)	(344,282)
Change in fair value of mortgage servicing rights, mortgage servicing liabilities and excess servicing spread	(222,426)	1,020,691
Mortgage servicing rights hedging gains	442,151	(1,036,570)
Capitalization of interest and advance on loans held for sale at fair value	(90,177)	(18,131)
Amortization of debt issuance cost	7,297	2,209
Results of real estate acquired in settlement of loans	(780)	707
Stock based compensation expense	10,877	12,368
(Reversal of) Provision for servicing advance losses	(20,536)	3,806
Impairment of capitalized software	728
Depreciation and amortization	7,632	5,352
Amortization of right-to-use assets	3,382	2,985
Origination of loans held for sale	(14,314,637)	(4,954,316)
Purchase of loans held for sale from non-affiliates	(1,443,255)	(620,859)
Purchase of loans from Ginnie Mae securities and early buyout investors for modification and subsequent sale	(4,355,102)	(2,299,262)
Sale to non-affiliates and principal payments of loans held for sale	37,268,200	19,337,017
Repurchase of loans subject to representations and warranties	(17,986)	(16,282)
Sale of real estate acquired in settlement of loans	4,946	9,459
Decrease in servicing advances	48,372	18,467
Decrease in other assets	22,912	628
Increase in accounts payable and accrued expenses	46,896	21,866
Decrease in operating lease liabilities	(4,066)	(3,469)
Net cash used in operating activities	(1,248,016)	(730,284)
Cash flow from investing activities
(Increase) decrease in short-term investments	(9,633)	72,727
Net settlement of derivative financial instruments used for hedging of mortgage servicing rights	(527,458)	942,005
Purchase of mortgage servicing rights		(24,104)
Purchase of furniture, fixtures, equipment and leasehold improvements	(2,738)	(994)
Acquisition of capitalized software	(10,056)	(14,108)
Increase in margin deposits	245,505	132,953
Net cash (used in) provided by investing activities	(223,518)	1,116,225
Cash flow from financing activities
Sale of assets under agreements to repurchase	35,805,822	20,510,531
Repurchase of assets sold under agreements to repurchase	(34,613,141)	(20,205,416)
Issuance of mortgage loan participation purchase and sale certificates	6,339,539	5,273,329
Repayment of mortgage loan participation purchase and sale certificates	(6,342,269)	(5,242,527)
Repayments of obligations under capital lease	(1,396)	(2,665)
Issuance of unsecured senior notes	650,000
Repayment of excess servicing spread financing	(134,624)	(9,308)
Payment of debt issuance costs	(13,475)	(3,388)
Issuance of common stock pursuant to exercise of stock options	1,670	3,082
Payment of withholding taxes relating to stock-based compensation	(8,546)	(5,265)
Payment of dividend to holders of common stock	(14,375)	(9,733)
Repurchase of common stock	(288,519)	(4,121)
Net cash provided by financing activities	1,380,686	304,519
Net (decrease) increase in cash and restricted cash	(90,848)	690,460
Cash and restricted cash at beginning of year	532,781	188,578
Cash and restricted cash at end of year	441,933	879,038
Cash	441,870	878,826
Restricted cash included in Other assets	63	212
PMT
Adjustments to reconcile net income to net cash used in operating activities:
Accrual of interest on excess servicing spread financing payable to PennyMac Mortgage Investment Trust	1,280	1,974
Change in fair value of investment in common shares of PennyMac Mortgage Investment Trust	(365)	875
Purchase of loans held for sale from PennyMac Mortgage Investment Trust	(18,420,615)	(14,509,209)
Sale to Penny Mac Mortgage Investment Trust of loans held for sale		2,246,127
Decrease (increase) in receivable from affiliates	14,878	(10,133)
Increase (decrease) in payable to affiliate	10,696	(17,019)
Increase in income taxes payable	129,155	108,474
Cash flow from investing activities
Net change in assets purchased from PMT under agreement to resell	$ 80,862	$ 7,746