Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segments and Related Information
Number of segments | segment	3
Revenues:
Net gains on loans held for sale at fair value	$ 162,441	$ 104,385
Loan origination fees	36,371	31,390
Fulfillment fees from PennyMac Mortgage Investment Trust	4,016	11,923
Net loan servicing fees	100,954	148,837
Net interest expense:
Interest income	156,426	128,478
Interest expense, before non-segment activities	165,769	131,771
Net interest expense, before non-segment activities	(9,343)	(3,293)
Management fees from PennyMac Mortgage Investment Trust	7,188	7,257
Other	4,033	2,363
Total net revenues, before non-segment activities	305,660	302,862
Expenses	261,777	264,715
Income before provision for income taxes	43,883	38,147
Assets:
Segment assets at year end	19,801,741		$ 18,844,563
Operating segment
Assets:
Segment assets at year end	19,801,741	20,103,185
Operating segment | Investment management
Net interest expense:
Interest income	84
Net interest expense, before non-segment activities	84
Management fees from PennyMac Mortgage Investment Trust	7,188	7,257
Other	2,119	2,012
Total net revenues, before non-segment activities	9,391	9,269
Expenses	6,336	8,929
Income before provision for income taxes	3,055	340
Assets:
Segment assets at year end	14,684	25,300
Operating segment | Mortgage banking
Revenues:
Net gains on loans held for sale at fair value	162,441	104,385
Loan origination fees	36,371	31,390
Fulfillment fees from PennyMac Mortgage Investment Trust	4,016	11,923
Net loan servicing fees	100,954	148,837
Net interest expense:
Interest income	156,342	128,478
Interest expense, before non-segment activities	165,769	131,771
Net interest expense, before non-segment activities	(9,427)	(3,293)
Other	1,914	351
Total net revenues, before non-segment activities	296,269	293,593
Expenses	255,441	255,786
Income before provision for income taxes	40,828	37,807
Assets:
Segment assets at year end	19,787,057	20,077,885
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	141,431	74,726
Loan origination fees	36,371	31,390
Fulfillment fees from PennyMac Mortgage Investment Trust	4,016	11,923
Net interest expense:
Interest income	63,931	56,993
Interest expense, before non-segment activities	61,896	54,083
Net interest expense, before non-segment activities	2,035	2,910
Other	818	574
Total net revenues, before non-segment activities	184,671	121,523
Expenses	148,779	141,163
Income before provision for income taxes	35,892	(19,640)
Assets:
Segment assets at year end	5,413,277	7,543,466
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	21,010	29,659
Net loan servicing fees	100,954	148,837
Net interest expense:
Interest income	92,411	71,485
Interest expense, before non-segment activities	103,873	77,688
Net interest expense, before non-segment activities	(11,462)	(6,203)
Other	1,096	(223)
Total net revenues, before non-segment activities	111,598	172,070
Expenses	106,662	114,623
Income before provision for income taxes	4,936	57,447
Assets:
Segment assets at year end	$ 14,373,780	$ 12,534,419