v3.26.1
Derivative and Credit Risk Transfer Strip Assets and Liabilities - Derivative Assets and Derivative and Credit Risk Transfer Strip Liabilities at Fair Value and Related Margin Deposits (Detail) - USD ($)
Mar. 31, 2026
Dec. 31, 2025
Derivatives Fair Value [Line Items]    
Margin deposits (received from) placed with derivative counterparties included in derivative balances above, net $ (22,711,000) $ 21,710,000
Derivative assets pledged to secure:    
Assets Sold Under Agreements to Repurchase and Notes payable secured by credit risk transfer and mortgag servicing assets 2,396,545,000 2,258,128,000
Derivative assets related to CRT Derivatives [Member]    
Derivative assets pledged to secure:    
Assets Sold Under Agreements to Repurchase and Notes payable secured by credit risk transfer and mortgag servicing assets 30,174,000 32,659,000
Penny Mac Financial Services Affiliated Entity [Member]    
Derivatives Fair Value [Line Items]    
Total derivatives assets before netting 3,838,000 6,389,000
Derivative assets, Netting (15,000) (142,000)
Total derivative assets after netting 3,823,000 6,247,000
Derivative assets pledged to secure:    
Total derivative liabilities 5,901,000 2,399,000
Derivative liabilities, Netting (15,000) (142,000)
Total derivative liabilities after netting 5,886,000 2,257,000
Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Total derivatives assets before netting 76,623,000 44,551,000
Derivative assets, Netting (25,857,000) 5,145,000
Total derivative assets after netting 50,766,000 49,696,000
Derivative assets pledged to secure:    
Total derivative liabilities 20,413,000 17,498,000
Derivative liabilities, Netting (3,146,000) (16,565,000)
Total derivative liabilities after netting 17,267,000 933,000
Nonaffiliates [Member] | CRT Derivatives [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 4,046,852,000 455,682,000
Total derivatives assets before netting [1] 30,174,000 32,659,000
Derivative assets pledged to secure:    
Total derivative liabilities [1] 0 0
Forward Purchase Contracts [Member] | Penny Mac Financial Services Affiliated Entity [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [2] 92,618,000 [1] 250,638,000
Total derivatives assets before netting 1,225,000 1,784,000
Derivative assets pledged to secure:    
Total derivative liabilities 15,000 142,000
Forward Purchase Contracts [Member] | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 6,632,514,000 3,703,628,000
Total derivatives assets before netting [1] 1,492,000 4,113,000
Derivative assets pledged to secure:    
Total derivative liabilities [1] 8,491,000 158,000
Forward Sale Contracts [Member] | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 9,957,359,000 7,933,760,000
Total derivatives assets before netting [1] 31,957,000 2,381,000
Derivative assets pledged to secure:    
Total derivative liabilities [1] 11,922,000 17,340,000
Interest Rate Lock Commitments [Member] | Penny Mac Financial Services Affiliated Entity [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [2] 1,338,161,000 1,207,859,000
Total derivatives assets before netting 2,613,000 4,605,000
Derivative assets pledged to secure:    
Total derivative liabilities 5,886,000 2,257,000
Call Options on Interest Rate Futures Purchase Contracts [Member] | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 1,712,500,000 3,250,000,000
Total derivatives assets before netting [1] 2,141,000 1,289,000
Derivative assets pledged to secure:    
Total derivative liabilities [1] 0 0
Put Options On Interest Rate Futures Purchase Contracts | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 2,375,000,000 2,500,000,000
Total derivatives assets before netting [1] 10,859,000 4,109,000
Derivative assets pledged to secure:    
Total derivative liabilities [1] 0 0
Swap Futures [Member] | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 790,200,000 751,200,000
Total derivatives assets before netting [1] 0 0
Derivative assets pledged to secure:    
Total derivative liabilities [1] 0 0
Bond Futures [Member] | Nonaffiliates [Member]    
Derivatives Fair Value [Line Items]    
Notional amount [1],[2] 1,571,100,000 1,896,100,000
Total derivatives assets before netting [1] 0 0
Derivative assets pledged to secure:    
Total derivative liabilities [1] $ 0 $ 0
[1] All hedging derivatives are interest rate derivatives that are used as economic hedges.
[2] Notional amounts provide an indication of the volume of the Company’s derivative activity.