v3.26.3
Borrowings - Schedule of Assets Held as Collateral Related to Secured Borrowings (Details) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2026
Aug. 30, 2026
Apr. 30, 2026
Jan. 31, 2026
Dec. 31, 2025
Debt Instrument [Line Items]          
Cash and cash equivalents $ 176.0       $ 180.5
Restricted cash 99.9       84.1
Mortgage servicing rights (MSRs), at fair value 3,360.6       2,825.3
Advances, net 375.1       483.4
Loans held for sale 2,747.3       1,891.7
Receivables, net ($84.3 and $64.2 related to VIEs) 270.0       189.8
REO ($145.2 and $81.0 related to VIEs) 156.2       83.8
Total Assets 11,320.9       16,170.6
Ginnie Mae Mortgage Servicing Rights Financing Facility | Secured Debt          
Debt Instrument [Line Items]          
Uncommitted available borrowing capacity 575.0 $ 575.0 $ 500.0 $ 450.0 $ 400.0
Asset Pledged as Collateral with Right | Ginnie Mae Mortgage Servicing Rights Financing Facility | Secured Debt          
Debt Instrument [Line Items]          
Proceeds from Lines of Credit 36.4        
Assets          
Debt Instrument [Line Items]          
Cash and cash equivalents 176.0        
Restricted cash 99.9        
Mortgage servicing rights (MSRs), at fair value 2,646.9        
Transferred MSRs, Including ESS 713.7        
Advances, net 375.1        
Loans held for sale 2,747.3        
Loans held for investment, at fair value 3,350.0        
Unsecuritized loans 12.6        
Receivables, net ($84.3 and $64.2 related to VIEs) 270.0        
REO ($145.2 and $81.0 related to VIEs) 156.2        
Total Assets 10,547.7        
Assets, Available Cash Held By Regulated Subsidiary Guarantors 153.7        
Pledged Assets          
Debt Instrument [Line Items]          
Cash and cash equivalents 0.0        
Restricted cash 49.7        
Mortgage servicing rights (MSRs), at fair value 2,653.1        
Transferred MSRs, Including ESS 713.7        
Advances, net 335.8        
Loans held for sale 2,688.6        
Loans held for investment, at fair value 3,350.0        
Unsecuritized loans 3.8        
Receivables, net ($84.3 and $64.2 related to VIEs) 147.7        
REO ($145.2 and $81.0 related to VIEs) 145.2        
Collateralized Debt Obligations [Member]          
Debt Instrument [Line Items]          
Cash and cash equivalents 0.0        
Restricted cash 0.0        
Mortgage servicing rights (MSRs), at fair value 1,645.5        
Transferred MSRs, Including ESS 631.1        
Advances, net 295.8        
Loans held for sale 2,898.8        
Loans held for investment, at fair value 3,335.1        
Unsecuritized loans 3.4        
Receivables, net ($84.3 and $64.2 related to VIEs) 160.7        
REO ($145.2 and $81.0 related to VIEs) 169.3        
Total Assets 9,139.7        
Senior Lien | Collateralized Debt Obligations [Member]          
Debt Instrument [Line Items]          
Transferred MSRs, ESS Financing Liabilities 18.0        
Senior Lien | Asset Pledged as Collateral with Right          
Debt Instrument [Line Items]          
Total Assets $ 10,087.6