v3.25.4
SERVICING - Schedules of Geographic Concentration of the Loans (Details) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 11,298,223 $ 8,096,883 $ 5,195,599
% of Total 100.00% 100.00% 100.00%
California | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 2,872,702 $ 2,146,371 $ 1,449,585
California | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 25.40% 26.50% 27.90%
Florida | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 1,357,888 $ 990,404 $ 593,697
Florida | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 12.00% 12.20% 11.40%
Arizona | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 562,655 $ 429,469 $ 270,442
Arizona | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 5.00% 5.30% 5.20%
Georgia | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 521,330 $ 407,651 $ 278,231
Georgia | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 4.60% 5.00% 5.40%
Washington | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 456,709 $ 362,370 $ 261,653
Washington | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 4.00% 4.50% 5.00%
New Jersey | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 415,090 $ 320,124 $ 211,344
New Jersey | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 3.70% 4.00% 4.10%
North Carolina | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 327,759 $ 261,013 $ 198,984
North Carolina | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 2.90% 3.20% 3.80%
Virginia | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 360,311 $ 239,559 $ 156,333
Virginia | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 3.20% 3.00% 3.00%
Virginia | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans   $ 241,844  
Virginia | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total   3.00%  
Colorado | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 305,980 $ 241,844 $ 168,289
Colorado | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 2.70% 3.00% 3.20%
Colorado | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans   $ 239,559  
Colorado | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total   3.00%  
Ohio | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 350,075 $ 227,069 $ 141,239
Ohio | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 3.10% 2.80% 2.70%
Other | Geographic Distribution, Foreign      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 2,800 $ 0  
Other | Concentration Risk      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
UPB of Underlying Loans $ 3,767,724 $ 2,471,009 $ 1,465,802
Other | Concentration Risk | Loans Underlying Servicing Assets      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
% of Total 33.40% 30.50% 28.20%