Transactions with Affiliates - Correspondent Production (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Sep. 12, 2016	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
MBS Agreement
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.35%
Fulfillment fee as a percent of UPB of all other mortgage loans, excluding Ginnie Mae mortgage loans	0.50%
MSR Recapture Agreement
Transactions with Affiliates
Related party transaction, automatic renewal period	18 months
Lending activity between the entity and affiliate
Minimum percent of total UPB of loans originated from refinancing of loans which a related party previously held the MSR required to be transferred	30.00%
PMT
Lending activity between the entity and affiliate
Total of gain on sale of loans and MSR recapture		$ 60,662	$ 18,565	$ 122,996	$ 45,878
Sale of loans held for sale to PMT				4,095,079	2,336,162
Fulfillment fee revenue		45,149	26,256	102,313	52,759
Proceeds from sale of mortgage loans held for sale to PennyMac Mortgage Investment Trust				4,095,079	2,336,162
PMT | MBS Agreement | Minimum
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.02%
PMT | MBS Agreement | Maximum
Transactions with Affiliates
The administrative fee plus accrued interest and sourcing fee percent	0.035%
PMT | Loan Lending
Lending activity between the entity and affiliate
Net gain on loans held for sale to PMT		62,558	19,722	127,423	49,396
Mortgage servicing rights and excess servicing spread recapture incurred		(1,896)	(1,157)	(4,427)	(3,518)
Total of gain on sale of loans and MSR recapture		60,662	18,565	122,996	45,878
Sale of loans held for sale to PMT		1,876,358	908,525	4,095,079	2,336,162
Tax service fee		4,222	2,119	9,567	4,869
Fulfillment fee revenue		45,149	26,256	102,313	52,759
Unpaid principal balance of loans fulfilled for PMT		16,647,172	7,517,883	35,523,802	17,139,884
Sourcing fees paid		4,206	2,689	9,355	8,221
Unpaid principal balance of loans purchased from PMT		14,022,222	8,916,654	31,183,950	27,404,022
Proceeds from sale of mortgage loans held for sale to PennyMac Mortgage Investment Trust		$ 1,876,358	$ 908,525	$ 4,095,079	$ 2,336,162