Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segments and Related Information
Number of operating segments | segment	2
Number of reportable segments | segment	2
Revenues:
Net gains on loans held for sale at fair value	$ 221,037	$ 162,441
Loan origination fees	46,611	36,371
Fulfillment fees from PennyMac Mortgage Investment Trust	5,290	4,016
Net loan servicing fees	164,286	100,954
Management fees	7,012	7,188
Net interest income (expense):
Interest income	189,871	156,426
Interest expense	208,082	165,769
Net interest income (expense)	(18,211)	(9,343)
Other	4,878	4,033
Total net revenues	430,903	305,660
Expenses:
Compensation	181,988	146,376
Loan origination	44,096	30,568
Technology	40,197	35,967
Servicing	21,875	16,104
Professional services	9,037	9,262
Occupancy and equipment	8,382	8,676
Marketing and advertising	9,432	3,671
Other	11,700	11,153
Total expenses	326,707	261,777
Income before provision for income taxes	104,196	43,883
Acquisition of:
Segment assets at end of quarter	23,872,876	19,801,741	$ 26,086,887
Capitalized software	7,137	3,864
Furniture, fixtures, equipment and building improvements	371	918
Amortization of capitalized software	11,981	12,181
Depreciation and amortization of furniture, fixtures, equipment and building improvements	13,896	14,164
Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	1,915	1,983
Operating segment
Revenues:
Net gains on loans held for sale at fair value	221,037	162,441
Loan origination fees	46,611	36,371
Fulfillment fees from PennyMac Mortgage Investment Trust	5,290	4,016
Net loan servicing fees	164,286	100,954
Net interest income (expense):
Interest income	189,422	155,912
Interest expense	208,082	165,769
Net interest income (expense)	(18,660)	(9,857)
Other	(42)	623
Total net revenues	418,522	294,548
Expenses:
Compensation	151,839	122,593
Loan origination	44,096	30,568
Technology	35,485	32,531
Servicing	21,875	16,104
Professional services	4,815	3,410
Occupancy and equipment	6,857	7,043
Marketing and advertising	8,396	3,625
Other	7,215	6,342
Total expenses	280,578	222,216
Income before provision for income taxes	137,944	72,332
Acquisition of:
Segment assets at end of quarter	23,807,703	19,709,489
Capitalized software	7,137	3,751
Furniture, fixtures, equipment and building improvements	216	861
Amortization of capitalized software	11,887	11,689
Operating segment | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	1,613	1,656
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	187,145	141,431
Loan origination fees	46,611	36,371
Fulfillment fees from PennyMac Mortgage Investment Trust	5,290	4,016
Net interest income (expense):
Interest income	85,288	63,371
Interest expense	76,526	61,896
Net interest income (expense)	8,762	1,475
Other	131	116
Total net revenues	247,939	183,409
Expenses:
Compensation	98,869	70,193
Loan origination	44,096	30,568
Technology	25,100	22,768
Professional services	3,134	2,062
Occupancy and equipment	4,128	4,138
Marketing and advertising	8,023	3,596
Other	2,646	1,406
Total expenses	185,996	134,731
Income before provision for income taxes	61,943	48,678
Acquisition of:
Segment assets at end of quarter	7,346,079	5,376,570
Capitalized software	5,409	3,441
Furniture, fixtures, equipment and building improvements	187	252
Amortization of capitalized software	10,221	9,486
Operating segment | Mortgage banking Production | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	968	959
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	33,892	21,010
Net loan servicing fees	164,286	100,954
Net interest income (expense):
Interest income	104,134	92,541
Interest expense	131,556	103,873
Net interest income (expense)	(27,422)	(11,332)
Other	(173)	507
Total net revenues	170,583	111,139
Expenses:
Compensation	52,970	52,400
Technology	10,385	9,763
Servicing	21,875	16,104
Professional services	1,681	1,348
Occupancy and equipment	2,729	2,905
Marketing and advertising	373	29
Other	4,569	4,936
Total expenses	94,582	87,485
Income before provision for income taxes	76,001	23,654
Acquisition of:
Segment assets at end of quarter	16,461,624	14,332,919
Capitalized software	1,728	310
Furniture, fixtures, equipment and building improvements	29	609
Amortization of capitalized software	1,666	2,203
Operating segment | Mortgage banking Servicing | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	645	697
Corporate and other
Revenues:
Management fees	7,012	7,188
Net interest income (expense):
Interest income	449	514
Net interest income (expense)	449	514
Other	4,920	3,410
Total net revenues	12,381	11,112
Expenses:
Compensation	30,149	23,783
Technology	4,712	3,436
Professional services	4,222	5,852
Occupancy and equipment	1,525	1,633
Marketing and advertising	1,036	46
Other	4,485	4,811
Total expenses	46,129	39,561
Income before provision for income taxes	(33,748)	(28,449)
Acquisition of:
Segment assets at end of quarter	65,173	92,252
Capitalized software		113
Furniture, fixtures, equipment and building improvements	155	57
Amortization of capitalized software	94	492
Corporate and other | Furniture, Fixtures, Equipment and Building Improvements
Acquisition of:
Depreciation and amortization of furniture, fixtures, equipment and building improvements	$ 302	$ 327