Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segments and Related Information
Number of segments | segment			3
Revenues:
Net gains on loans held for sale at fair value	$ 176,064	$ 141,419	$ 338,505	$ 245,804
Loan origination fees	42,075	38,968	78,446	70,358
Fulfillment fees from PennyMac Mortgage Investment Trust	4,427	5,441	8,443	17,364
Net loan servicing fees	167,604	146,078	268,558	294,915
Net interest expense:
Interest income	200,811	172,952	357,237	301,430
Interest expense, before non-segment activities	207,871	178,642	373,640	310,413
Net interest expense, before non-segment activities	(7,060)	(5,690)	(16,403)	(8,983)
Management fees from PennyMac Mortgage Investment Trust	7,133	7,078	14,321	14,335
Other	15,884	3,253	19,917	5,616
Total net revenues, before non-segment activities	406,127	336,547	711,787	639,409
Expenses	272,273	263,630	534,050	528,345
Income before provision for income taxes	133,854	72,917	177,737	111,064
Assets:
Segment assets at year end	21,577,565	17,984,468	21,577,565	17,984,468	$ 18,844,563
Operating segment
Assets:
Segment assets at year end	21,577,565	17,984,468	21,577,565	17,984,468
Operating segment | Investment management
Net interest expense:
Interest income	79		163
Net interest expense, before non-segment activities	79		163
Management fees from PennyMac Mortgage Investment Trust	7,133	7,078	14,321	14,335
Other	2,125	2,421	4,244	4,433
Total net revenues, before non-segment activities	9,337	9,499	18,728	18,768
Expenses	5,302	7,541	11,638	16,470
Income before provision for income taxes	4,035	1,958	7,090	2,298
Assets:
Segment assets at year end	13,320	23,182	13,320	23,182
Operating segment | Mortgage banking
Revenues:
Net gains on loans held for sale at fair value	176,064	141,419	338,505	245,804
Loan origination fees	42,075	38,968	78,446	70,358
Fulfillment fees from PennyMac Mortgage Investment Trust	4,427	5,441	8,443	17,364
Net loan servicing fees	167,604	146,078	268,558	294,915
Net interest expense:
Interest income	200,732	172,952	357,074	301,430
Interest expense, before non-segment activities	207,871	178,642	373,640	310,413
Net interest expense, before non-segment activities	(7,139)	(5,690)	(16,566)	(8,983)
Other	13,759	832	15,673	1,183
Total net revenues, before non-segment activities	396,790	327,048	693,059	620,641
Expenses	266,971	256,089	522,412	511,875
Income before provision for income taxes	129,819	70,959	170,647	108,766
Assets:
Segment assets at year end	21,564,245	17,961,286	21,564,245	17,961,286
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	154,317	126,249	295,748	200,975
Loan origination fees	42,075	38,968	78,446	70,358
Fulfillment fees from PennyMac Mortgage Investment Trust	4,427	5,441	8,443	17,364
Net interest expense:
Interest income	84,613	75,423	148,544	132,416
Interest expense, before non-segment activities	83,376	75,994	145,272	130,077
Net interest expense, before non-segment activities	1,237	(571)	3,272	2,339
Other	509	528	1,327	1,102
Total net revenues, before non-segment activities	202,565	170,615	387,236	292,138
Expenses	161,286	146,200	310,065	287,363
Income before provision for income taxes	41,279	24,415	77,171	4,775
Assets:
Segment assets at year end	6,477,599	4,976,152	6,477,599	4,976,152
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	21,747	15,170	42,757	44,829
Net loan servicing fees	167,604	146,078	268,558	294,915
Net interest expense:
Interest income	116,119	97,529	208,530	169,014
Interest expense, before non-segment activities	124,495	102,648	228,368	180,336
Net interest expense, before non-segment activities	(8,376)	(5,119)	(19,838)	(11,322)
Other	13,250	304	14,346	81
Total net revenues, before non-segment activities	194,225	156,433	305,823	328,503
Expenses	105,685	109,889	212,347	224,512
Income before provision for income taxes	88,540	46,544	93,476	103,991
Assets:
Segment assets at year end	$ 15,086,646	$ 12,985,134	$ 15,086,646	$ 12,985,134