v3.25.4
Commitments and Contingencies - Narrative (Details) - USD ($)
 4 Months Ended 12 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
May 04, 2023
Loss Contingencies [Line Items]        
Service fee (percent) 0.15% 0.15%    
IDA balance floor amount       $ 60,000,000,000
IDA balance ceiling amount       $ 90,000,000,000
BDA balances moved $ 6,700,000,000      
Ending IDA balance 76,300,000,000 $ 76,300,000,000 $ 87,600,000,000  
Fixed-rate obligation IDA balance 59,600,000,000 59,600,000,000 66,600,000,000  
Floating-rate obligation IDA balance 16,700,000,000 16,700,000,000 21,000,000,000.0  
Guarantees        
Loss Contingencies [Line Items]        
Liability for guarantees $ 0 0    
Residential real estate | First Mortgages        
Loss Contingencies [Line Items]        
Purchases during period   6,700,000,000 4,200,000,000  
Residential real estate | HELOCs        
Loss Contingencies [Line Items]        
Purchases during period   $ 231,000,000 $ 157,000,000