Segments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Segments and Related Information
Number of reportable segments | segment	2
Revenues:
Net gains on loans held for sale at fair value	$ 817,368	$ 545,943	$ 791,633
Loan origination fees	185,700	146,118	169,859
Fulfillment fees from PennyMac Mortgage Investment Trust	26,291	27,826	67,991
Net loan servicing fees	533,655	642,600	951,329
Management fees	28,623	28,762	31,065
Net interest income (expense):
Interest income	793,566	632,924	294,062
Interest expense	819,348	637,777	335,427
Net interest income (expense)	(25,782)	(4,853)	(41,365)
Other	27,876	15,260	15,243
Total net revenues	1,593,731	1,401,656	1,985,755
Expenses:
Compensation	632,738	576,964	735,231
Loan origination	164,092	114,500	173,622
Technology	149,547	143,152	139,950
Servicing	105,997	69,433	59,628
Professional services	37,992	60,521	73,270
Occupancy and equipment	32,898	36,558	40,124
Marketing and advertising	21,969	17,631	46,762
Legal settlements	1,591	162,770	4,649
Other	45,881	36,496	47,272
Total expenses	1,192,705	1,218,025	1,320,508
Income before provision for income taxes	401,026	183,631	665,247
Acquisition of:
Segment assets at year end	26,086,887	18,844,563	16,822,584
Capitalized software	20,382	34,784	71,935
Furniture, fixtures, equipment and building improvements	1,715	1,386	7,159
Amortization of capitalized software	48,169	43,462	23,955
Depreciation and amortization of furniture, fixtures, equipment and building improvements	55,984	53,214	34,409
Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	$ 7,815	9,752	10,454
Mortgage banking
Segments and Related Information
Number of operating segments | segment	2
Number of reportable segments | segment	2
Operating segment
Revenues:
Net gains on loans held for sale at fair value	$ 817,368	545,943	791,633
Loan origination fees	185,700	146,118	169,859
Fulfillment fees from PennyMac Mortgage Investment Trust	26,291	27,826	67,991
Net loan servicing fees	533,655	642,600	951,329
Net interest income (expense):
Interest income	791,702	630,554	293,160
Interest expense	819,348	637,777	335,427
Net interest income (expense)	(27,646)	(7,223)	(42,267)
Other	1,698	3,913	3,560
Total net revenues	1,537,066	1,359,177	1,942,105
Expenses:
Compensation	520,209	475,449	590,216
Loan origination	164,092	114,500	173,622
Technology	135,114	128,429	123,082
Servicing	105,997	69,433	59,628
Professional services	18,112	18,310	30,269
Occupancy and equipment	26,825	29,127	34,006
Marketing and advertising	20,418	16,303	41,098
Legal settlements	(30)	853
Other	30,096	22,303	28,172
Total expenses	1,020,833	874,707	1,080,093
Income before provision for income taxes	516,233	484,470	862,012
Acquisition of:
Segment assets at year end	26,019,630	18,596,526	16,674,088
Capitalized software	19,841	32,920	67,536
Furniture, fixtures, equipment and building improvements	1,504	1,190	6,661
Amortization of capitalized software	47,041	41,219	21,614
Operating segment | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	6,547	8,190	8,876
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	726,720	453,063	599,895
Loan origination fees	185,700	146,118	169,859
Fulfillment fees from PennyMac Mortgage Investment Trust	26,291	27,826	67,991
Net interest income (expense):
Interest income	321,210	272,307	134,206
Interest expense	318,750	254,890	108,072
Net interest income (expense)	2,460	17,417	26,134
Other	531	250	441
Total net revenues	941,702	644,674	864,320
Expenses:
Compensation	315,838	274,447	384,884
Loan origination	164,092	114,500	173,622
Technology	95,603	88,086	81,826
Professional services	11,206	10,825	22,769
Occupancy and equipment	15,683	18,353	21,653
Marketing and advertising	20,138	16,125	40,419
Legal settlements		853
Other	7,911	5,407	8,348
Total expenses	630,471	528,596	733,521
Income before provision for income taxes	311,231	116,078	130,799
Acquisition of:
Segment assets at year end	8,431,612	4,560,323	3,617,627
Capitalized software	16,156	32,504	66,171
Furniture, fixtures, equipment and building improvements	465	199	5,146
Amortization of capitalized software	39,160	31,285	11,653
Operating segment | Mortgage banking Production | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	3,743	5,225	5,832
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	90,648	92,880	191,738
Net loan servicing fees	533,655	642,600	951,329
Net interest income (expense):
Interest income	470,492	358,247	158,954
Interest expense	500,598	382,887	227,355
Net interest income (expense)	(30,106)	(24,640)	(68,401)
Other	1,167	3,663	3,119
Total net revenues	595,364	714,503	1,077,785
Expenses:
Compensation	204,371	201,002	205,332
Technology	39,511	40,343	41,256
Servicing	105,997	69,433	59,628
Professional services	6,906	7,485	7,500
Occupancy and equipment	11,142	10,774	12,353
Marketing and advertising	280	178	679
Legal settlements	(30)
Other	22,185	16,896	19,824
Total expenses	390,362	346,111	346,572
Income before provision for income taxes	205,002	368,392	731,213
Acquisition of:
Segment assets at year end	17,588,018	14,036,203	13,056,461
Capitalized software	3,685	416	1,365
Furniture, fixtures, equipment and building improvements	1,039	991	1,515
Amortization of capitalized software	7,881	9,934	9,961
Operating segment | Mortgage banking Servicing | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	2,804	2,965	3,044
Corporate and other
Revenues:
Management fees	28,623	28,762	31,065
Net interest income (expense):
Interest income	1,864	2,370	902
Net interest income (expense)	1,864	2,370	902
Other	26,178	11,347	11,683
Total net revenues	56,665	42,479	43,650
Expenses:
Compensation	112,529	101,515	145,015
Technology	14,433	14,723	16,868
Professional services	19,880	42,211	43,001
Occupancy and equipment	6,073	7,431	6,118
Marketing and advertising	1,551	1,328	5,664
Legal settlements	1,621	161,917	4,649
Other	15,785	14,193	19,100
Total expenses	171,872	343,318	240,415
Income before provision for income taxes	(115,207)	(300,839)	(196,765)
Acquisition of:
Segment assets at year end	67,257	248,037	148,496
Capitalized software	541	1,864	4,399
Furniture, fixtures, equipment and building improvements	211	196	498
Amortization of capitalized software	1,128	2,243	2,341
Corporate and other | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	$ 1,268	$ 1,562	$ 1,578