Transactions with Related Parties - Summary of Management Fee Expense (Detail) - PNMAC Capital Management LLC [Member] - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Related Party Transaction [Line Items] | ||||
| Total management fee incurred during the period | $ 6,762 | $ 6,912 | $ 20,334 | $ 20,793 |
| Average shareholders' equity amounts used to calculate base management fee expense | 1,788,469 | 1,828,365 | 1,812,550 | 1,853,613 |
| Base management fee [Member] | ||||
| Related Party Transaction [Line Items] | ||||
| Total management fee incurred during the period | 6,762 | 6,912 | 20,334 | 20,793 |
| Performance incentive fee [Member] | ||||
| Related Party Transaction [Line Items] | ||||
| Total management fee incurred during the period | $ 0 | $ 0 | $ 0 | $ 0 |
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- Definition Average shareholders' equity amounts used to calculate management fee expense. No definition available.
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- Definition Amount of expense for investment management fee, including, but not limited to, expense in connection with research, selection, supervision, and custody of investment. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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