Transactions with Related Parties - Summary of Loan Servicing Fees Earned and Mortgage Servicing Rights Recaptured Income Earned (Detail) - PennyMac Loan Services, LLC [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Loan servicing fees	$ 22,240	$ 20,257	$ 62,766	$ 61,023
Average MSR portfolio unpaid principal balance	227,804,449	231,333,064	229,174,686	231,333,990
MSR recapture fees	441	500	1,267	1,494
UPB of loans recaptured	71,370	77,403	207,651	270,720
Loans acquired for sale [Member]
Related Party Transaction [Line Items]
Loan servicing fees	158	112	342	569
Average investment in loans acquired for sale at fair value	1,069,653	868,808	1,002,719	1,613,347
Loans at fair value [Member]
Related Party Transaction [Line Items]
Loan servicing fees	60	33	185	184
Loans at fair value	1,388,368	1,437,418	1,401,643	1,479,525
Mortgage servicing rights [Member]
Related Party Transaction [Line Items]
Loan servicing fees	$ 22,022	$ 20,112	$ 62,239	$ 60,270