Transactions with Related Parties - Summary of Expenses (Detail) - PNMAC Capital Management LLC [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Related Party Transaction [Line Items]
Expenses incurred on the Company’s behalf, net		$ 2,779	$ 3,978	$ 9,193	$ 9,639
Common overhead incurred by PCM and its affiliates		2,000	2,140	3,944	3,961
Compensation		165	165	330	330
Total expenses incurred in transaction with affiliates		4,944	6,283	13,467	13,930
Payments and settlements during the quarter	[1]	$ 29,263	$ 30,872	$ 59,348	$ 63,256

[1] Payments and settlements include payments and netting settlements made pursuant to master netting agreements between the Company and PFSI for the operating, investing and financing activities itemized in this Note.