Related Party Transactions - Other Transactions, Reimbursement of Common Overhead Expenses (Details) - PennyMac Mortgage Investment Trust - USD ($)		3 Months Ended		6 Months Ended
	Sep. 12, 2016	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 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		$ 4,808,000	$ 9,237,000	$ 12,194,000	$ 11,309,000
Payments and settlements during the year		29,562,000	74,441,000	69,326,000	187,182,000
Common overhead incurred
Reimbursement of common overhead and expenses incurred on behalf of affiliates
Reimbursement of common overhead and expenses incurred by the Company		1,809,000	1,268,000	3,673,000	1,839,000
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	330,000	330,000
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		$ 2,834,000	$ 7,804,000	$ 8,191,000	$ 9,140,000