Related Party Transactions - Other Transactions, Reimbursement of Common Overhead Expenses (Details) - PennyMac Mortgage Investment Trust - USD ($)		3 Months Ended		9 Months Ended
	Sep. 12, 2016	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Transactions with Affiliates
Expense reimbursement amount, per quarter, relating to personnel	$ 165,000
Reimbursement of common overhead and expenses incurred on behalf of affiliates
Reimbursement of common overhead and expenses incurred by the Company		$ 3,444,000	$ 6,109,000	$ 15,638,000	$ 17,418,000
Payments and settlements during the year		41,509,000	51,020,000	110,835,000	238,202,000
Common overhead incurred
Reimbursement of common overhead and expenses incurred on behalf of affiliates
Reimbursement of common overhead and expenses incurred by the Company		2,574,000	1,548,000	6,247,000	3,387,000
Compensation
Reimbursement of common overhead and expenses incurred on behalf of affiliates
Reimbursement of common overhead and expenses incurred by the Company		165,000	165,000	495,000	495,000
Expenses incurred by related party (reporting entity), net
Reimbursement of common overhead and expenses incurred on behalf of affiliates
Reimbursement of common overhead and expenses incurred by the Company		$ 705,000	$ 4,396,000	$ 8,896,000	$ 13,536,000