Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segments and Related Information
Number of segments | segment			3
Revenues:
Net gains on loans held for sale at fair value	$ 141,419	$ 222,567	$ 245,804	$ 521,026
Loan origination fees	38,968	39,945	70,358	107,803
Fulfillment fees from PennyMac Mortgage Investment Trust	5,441	20,646	17,364	37,400
Net loan servicing fees	146,078	238,447	294,915	524,756
Net interest income (expense):
Interest income	172,952	49,864	301,430	103,746
Interest expense, before non-segment activities	178,642	71,127	310,413	148,434
Net interest expense, before non-segment activities	(5,690)	(21,263)	(8,983)	(44,688)
Management fees from PennyMac Mortgage Investment Trust	7,078	7,910	14,335	16,027
Other	3,253	3,263	5,616	6,695
Total net revenues, before non-segment activities	336,547	511,515	639,409	1,169,019
Expenses	263,630	333,989	528,345	756,973
Income before provision for income taxes	72,917	177,526	111,064	412,046
Assets:
Segment assets at period end	17,984,468	14,272,255	17,984,468	14,272,255	$ 16,822,584
Related Party
Revenues:
Net gains on loans held for sale at fair value	(509)	(4,752)	(994)	(14,404)
Loan origination fees	701	2,404	2,111	4,746
Related Party | PennyMac Mortgage Investment Trust
Revenues:
Net gains on loans held for sale at fair value	(509)	(4,752)	(994)	(14,404)
Operating segment
Assets:
Segment assets at period end	17,984,468	14,272,255	17,984,468	14,272,255
Operating segment | Investment management
Net interest income (expense):
Management fees from PennyMac Mortgage Investment Trust	7,078	7,910	14,335	16,027
Other	2,421	1,780	4,433	3,811
Total net revenues, before non-segment activities	9,499	9,690	18,768	19,838
Expenses	7,541	9,443	16,470	19,494
Income before provision for income taxes	1,958	247	2,298	344
Assets:
Segment assets at period end	23,182	26,599	23,182	26,599
Operating segment | Mortgage banking
Revenues:
Net gains on loans held for sale at fair value	141,419	222,567	245,804	521,026
Loan origination fees	38,968	39,945	70,358	107,803
Fulfillment fees from PennyMac Mortgage Investment Trust	5,441	20,646	17,364	37,400
Net loan servicing fees	146,078	238,447	294,915	524,756
Net interest income (expense):
Interest income	172,952	49,864	301,430	103,746
Interest expense, before non-segment activities	178,642	71,127	310,413	148,434
Net interest expense, before non-segment activities	(5,690)	(21,263)	(8,983)	(44,688)
Other	832	1,483	1,183	2,884
Total net revenues, before non-segment activities	327,048	501,825	620,641	1,149,181
Expenses	256,089	324,546	511,875	737,479
Income before provision for income taxes	70,959	177,279	108,766	411,702
Assets:
Segment assets at period end	17,961,286	14,245,656	17,961,286	14,245,656
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	126,249	152,895	200,975	374,505
Loan origination fees	38,968	39,945	70,358	107,803
Fulfillment fees from PennyMac Mortgage Investment Trust	5,441	20,646	17,364	37,400
Net interest income (expense):
Interest income	75,423	28,379	132,416	59,320
Interest expense, before non-segment activities	75,994	19,207	130,077	46,266
Net interest expense, before non-segment activities	(571)	9,172	2,339	13,054
Other	528	583	1,102	1,368
Total net revenues, before non-segment activities	170,615	223,241	292,138	534,130
Expenses	146,200	213,587	287,363	515,206
Income before provision for income taxes	24,415	9,654	4,775	18,924
Assets:
Segment assets at period end	4,976,152	3,735,706	4,976,152	3,735,706
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	15,170	69,672	44,829	146,521
Net loan servicing fees	146,078	238,447	294,915	524,756
Net interest income (expense):
Interest income	97,529	21,485	169,014	44,426
Interest expense, before non-segment activities	102,648	51,920	180,336	102,168
Net interest expense, before non-segment activities	(5,119)	(30,435)	(11,322)	(57,742)
Other	304	900	81	1,516
Total net revenues, before non-segment activities	156,433	278,584	328,503	615,051
Expenses	109,889	110,959	224,512	222,273
Income before provision for income taxes	46,544	167,625	103,991	392,778
Assets:
Segment assets at period end	$ 12,985,134	$ 10,509,950	$ 12,985,134	$ 10,509,950