CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flow from operating activities
Net income	$ 206,934	$ 181,498
Adjustments to reconcile net income to net cash used in operating activities:
Net gains on loans held for sale at fair value	(595,324)	(397,178)
Change in fair value of mortgage servicing rights and mortgage servicing liabilities	758,158	70,608
Mortgage servicing rights hedging results	224,371	531,565
Accrual of unearned discounts on mortgage-backed securities	(29,219)
Capitalization of interest on loans held for sale	(362)	(678)
Amortization of debt issuance costs	21,860	14,925
Change in fair value of investment in common shares of PennyMac Mortgage Investment Trust	51	(1)
Results of real estate acquired in settlement in loans	(330)	(978)
Stock-based compensation expense	21,314	20,839
Provision (reversal of provision) for servicing advance losses	13,974	(7,603)
Depreciation and amortization	42,165	39,122
Amortization of operating lease right-of-use assets	10,256	13,311
Purchase of loans held for sale from PennyMac Mortgage Investment Trust	(57,502,461)	(50,812,386)
Origination of loans held for sale	(12,069,838)	(8,277,117)
Purchase of loans held for sale from non-affiliates	(1,933,158)	(1,507,346)
Purchase of loans from Ginnie Mae securities and early buyout investors	(2,379,099)	(2,045,156)
Sale to non-affiliates and principal payment of loans held for sale	70,706,054	60,061,205
Sale of loans held for sale to PennyMac Mortgage Investment Trust	191,250
Repurchase of loans subject to representations and warranties	(70,700)	(38,943)
Decrease in servicing advances	194,088	248,115
(Increase) decrease in receivable from PennyMac Mortgage Investment Trust	(5,451)	8,229
Sale of real estate acquired in settlement of loans	37,840	25,039
Increase in other assets	(42,377)	(47,226)
Decrease in accounts payable and accrued expenses	(106,125)	(24,641)
Decrease in operating lease liabilities	(13,359)	(16,992)
Decrease in payable to PennyMac Mortgage Investment Trust	(127,710)	(107,968)
Increase in income taxes payable	62,664	57,249
Net cash used in operating activities	(2,384,534)	(2,012,508)
Cash flow from investing activities
(Increase) decrease in short-term investment	(657,666)	6,641
Purchase of principal-only stripped mortgage-backed securities	(935,356)
Repayment of principal-only stripped mortgage-backed securities	36,506
Sale of interest-only stripped mortgage-backed securities	121,520	98,066
Net settlement of derivative financial instruments used for hedging of mortgage servicing rights	(210,157)	(450,193)
Transfer of mortgage servicing rights relating to delinquent loans to Agency		305
Acquisition of capitalized software	(13,001)	(27,650)
Purchase of furniture, fixtures, equipment and leasehold improvements	(1,467)	(891)
Increase in margin deposits	(99,989)	(4,254)
Net cash used in investing activities	(1,759,610)	(377,976)
Cash flow from financing activities
Sale of assets under agreements to repurchase	77,065,706	61,277,758
Repurchase of assets sold under agreements to repurchase	(74,225,451)	(59,864,151)
Issuance of mortgage loan participation purchase and sale certificates	17,117,748	16,137,040
Repayment of mortgage loan participation purchase and sale certificates	(17,046,112)	(15,926,067)
Issuance of notes payable secured by mortgage servicing assets	725,000	880,000
Repayment of notes payable secured by mortgage servicing assets	(875,000)	(150,000)
Issuance of unsecured senior notes	650,000
Payment of debt issuance costs	(32,432)	(14,716)
Issuance of common stock by exercise of stock options	18,016	11,308
Payment of withholding taxes relating to stock-based compensation	(9,401)	(9,142)
Payment of dividends to holders of common stock	(36,487)	(31,206)
Repurchase of common stock		(71,575)
Net cash provided by financing activities	3,351,587	2,239,249
Net decrease in cash and restricted cash	(792,557)	(151,235)
Cash and restricted cash at beginning of period	938,371	1,328,539
Cash at end of period	145,814	1,177,304
Supplemental cash flow information:
Cash paid for interest	571,461	463,567
Cash paid (refunds received) for income taxes, net	2,064	(886)
Non-cash investing activities:
Mortgage servicing rights received from loan sales	1,532,709	1,299,992
Exchange of mortgage servicing spread for interest-only stripped mortgage-backed securities	121,520	98,066
Operating right-of-use assets recognized	1,388	2,893
Non-cash financing activities:
Issuance of common stock in settlement of directors' fees	$ 199	$ 102