Transactions with Related Parties - Summary of Correspondent Production Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	$ 1,665,796		$ 1,665,796		$ 669,018
PennyMac Loan Services, LLC [Member]
Related Party Transaction [Line Items]
Loan fulfillment fees earned by PLS	11,492	$ 5,531	19,935	$ 22,895
UPB of loans fulfilled by PLS	5,948,057	2,760,000	9,949,135	12,418,084
Sourcing fees received from PLS included in Net gains on loans acquired for sale	1,994	1,854	5,649	5,014
Purchases of loans acquired for sale from PLS	191,250	0	191,250	0
UPB of loans sold to PLS	19,935,648	18,539,428	56,489,624	50,141,246
Tax service fees paid to PLS	1,112	579	1,902	2,690
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	114,723		114,723		$ 168,303
PennyMac Loan Services, LLC [Member] | Government Guaranteed Or Insured [Member]
Related Party Transaction [Line Items]
UPB of loans sold to PLS	11,843,268	8,606,835	30,200,608	29,127,889
PennyMac Loan Services, LLC [Member] | Conventional Conforming [Member]
Related Party Transaction [Line Items]
UPB of loans sold to PLS	$ 8,092,380	$ 9,932,593	$ 26,289,016	$ 21,013,357