v3.26.1
Derivative and Credit Risk Transfer Strip Assets and Liabilities - Summary of Derivative Assets, Financial Instruments and Collateral Held by Counterparty (Detail) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Offsetting Assets [Line Items]    
Total derivative assets after netting $ 50,766 $ 49,696
Financial instruments 0 0
Cash collateral received 0 0
Net amount 50,766 49,696
CRT Derivatives [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 30,174 32,659
Financial instruments 0 0
Cash collateral received 0 0
Net amount 30,174 32,659
RJ O'Brien & Associates, LLC [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 13,000 5,398
Financial instruments 0 0
Cash collateral received 0 0
Net amount 13,000 5,398
Bank of America, N.A. [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 2,261 4,745
Financial instruments 0 0
Cash collateral received 0 0
Net amount 2,261 4,745
AB Carval [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 2,072 0
Financial instruments 0 0
Cash collateral received 0 0
Net amount 2,072 0
J.P. Morgan Securities LLC [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 1,348 102
Financial instruments 0 0
Cash collateral received 0 0
Net amount 1,348 102
National Life Group [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 579 0
Financial instruments 0 0
Cash collateral received 0 0
Net amount 579 0
Fannie Cap Markets [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 417 0
Financial instruments 0 0
Cash collateral received 0 0
Net amount 417 0
Morgan Stanley & Co. LLC [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 338 3,500
Financial instruments 0 0
Cash collateral received 0 0
Net amount 338 3,500
Wells Fargo Securities L L C    
Offsetting Assets [Line Items]    
Total derivative assets after netting 111 603
Financial instruments 0 0
Cash collateral received 0 0
Net amount 111 603
Nomura Holdings America Inc [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 59 137
Financial instruments 0 0
Cash collateral received 0 0
Net amount 59 137
Goldman Sachs & Co. LLC [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 950
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 950
Mizuho Financial Group [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 442
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 442
B N P Paribas [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 236
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 236
Citigroup Global Markets Inc. [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 217
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 217
Ellington Management [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 198
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 198
Metro Life Ins Co [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 151
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 151
Barclays Capital Inc [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 0 103
Financial instruments 0 0
Cash collateral received 0 0
Net amount 0 103
Other [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 407 255
Financial instruments 0 0
Cash collateral received 0 0
Net amount 407 255
Pennymac Financial Services Inc [Member]    
Offsetting Assets [Line Items]    
Total derivative assets after netting 3,823 6,247
Financial instruments 0 0
Cash collateral received 0 0
Net amount $ 3,823 $ 6,247