Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Segments and Related Information
Number of segments | segment			3
Revenues:
Net gains on loans held for sale at fair value	$ 222,567	$ 582,648	$ 521,026	$ 1,336,989
Loan origination fees	39,945	97,291	107,803	201,328
Fulfillment fees from PennyMac Mortgage Investment Trust	20,646	54,020	37,400	114,855
Net loan servicing fees	238,447	14,871	524,756	54,591
Net interest income (expense):
Interest income	49,864	80,797	103,746	162,878
Interest expense, before non-segment activities	71,127	102,431	148,434	210,144
Net interest expense, before non-segment activities	(21,263)	(21,634)	(44,688)	(47,266)
Management fees from PennyMac Mortgage Investment Trust	7,910	11,913	16,027	20,362
Other	3,263	3,143	6,695	6,079
Total net revenues, before non-segment activities	511,515	742,252	1,169,019	1,686,938
Expenses	333,989	462,737	756,973	901,415
Income before provision for income taxes	177,526	279,515	412,046	785,523
Assets:
Segment assets at quarter end	14,272,255	23,880,138	14,272,255	23,880,138	$ 18,776,612
PennyMac Mortgage Investment Trust
Revenues:
Net gains on loans held for sale at fair value	(4,752)	(11,548)	$ (14,404)	(25,796)
Net interest income (expense):
Interest income				387
Mortgage banking
Segments and Related Information
Number of segments | segment			2
Operating segment
Assets:
Segment assets at quarter end	14,272,255	23,880,138	$ 14,272,255	23,880,138
Operating segment | Investment management
Net interest income (expense):
Interest expense, before non-segment activities		3		6
Net interest expense, before non-segment activities		(3)		(6)
Management fees from PennyMac Mortgage Investment Trust	7,910	11,913	16,027	20,362
Other	1,780	1,588	3,811	2,730
Total net revenues, before non-segment activities	9,690	13,498	19,838	23,086
Expenses	9,443	9,349	19,494	17,568
Income before provision for income taxes	247	4,149	344	5,518
Assets:
Segment assets at quarter end	26,599	23,305	26,599	23,305
Operating segment | Mortgage banking
Revenues:
Net gains on loans held for sale at fair value	222,567	582,648	521,026	1,336,989
Loan origination fees	39,945	97,291	107,803	201,328
Fulfillment fees from PennyMac Mortgage Investment Trust	20,646	54,020	37,400	114,855
Net loan servicing fees	238,447	14,871	524,756	54,591
Net interest income (expense):
Interest income	49,864	80,797	103,746	162,878
Interest expense, before non-segment activities	71,127	102,428	148,434	210,138
Net interest expense, before non-segment activities	(21,263)	(21,631)	(44,688)	(47,260)
Other	1,483	1,555	2,884	3,349
Total net revenues, before non-segment activities	501,825	728,754	1,149,181	1,663,852
Expenses	324,546	453,388	737,479	883,847
Income before provision for income taxes	177,279	275,366	411,702	780,005
Assets:
Segment assets at quarter end	14,245,656	23,856,833	14,245,656	23,856,833
Operating segment | Mortgage banking Production
Revenues:
Net gains on loans held for sale at fair value	152,895	419,293	374,505	935,256
Loan origination fees	39,945	97,291	107,803	201,328
Fulfillment fees from PennyMac Mortgage Investment Trust	20,646	54,020	37,400	114,855
Net interest income (expense):
Interest income	28,379	31,830	59,320	61,361
Interest expense, before non-segment activities	19,207	36,913	46,266	74,985
Net interest expense, before non-segment activities	9,172	(5,083)	13,054	(13,624)
Other	583	630	1,368	1,227
Total net revenues, before non-segment activities	223,241	566,151	534,130	1,239,042
Expenses	213,587	321,709	515,206	631,705
Income before provision for income taxes	9,654	244,442	18,924	607,337
Assets:
Segment assets at quarter end	3,735,706	7,670,877	3,735,706	7,670,877
Operating segment | Mortgage banking Servicing
Revenues:
Net gains on loans held for sale at fair value	69,672	163,355	146,521	401,733
Net loan servicing fees	238,447	14,871	524,756	54,591
Net interest income (expense):
Interest income	21,485	48,967	44,426	101,517
Interest expense, before non-segment activities	51,920	65,515	102,168	135,153
Net interest expense, before non-segment activities	(30,435)	(16,548)	(57,742)	(33,636)
Other	900	925	1,516	2,122
Total net revenues, before non-segment activities	278,584	162,603	615,051	424,810
Expenses	110,959	131,679	222,273	252,142
Income before provision for income taxes	167,625	30,924	392,778	172,668
Assets:
Segment assets at quarter end	$ 10,509,950	$ 16,185,956	$ 10,509,950	$ 16,185,956