v3.26.1
Commitments and Contingencies - Narrative (Details) - USD ($)
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
May 04, 2023
Loss Contingencies [Line Items]        
Basis spread on variable rate (percent) 0.15%      
IDA balance floor amount       $ 60,000,000,000
IDA balance ceiling amount       $ 90,000,000,000
Additions (reductions) in deposit balance $ 1,100,000,000      
Ending IDA balance 73,600,000,000   $ 76,300,000,000  
Fixed-rate obligation IDA balance 59,600,000,000   59,600,000,000  
Floating-rate obligation IDA balance 14,000,000,000.0   $ 16,700,000,000  
Guarantees        
Loss Contingencies [Line Items]        
Liability for guarantees 0      
Residential real estate | First Mortgages        
Loss Contingencies [Line Items]        
Purchased during period 2,000,000,000.0 $ 963,000,000    
Residential real estate | HELOCs        
Loss Contingencies [Line Items]        
Purchased during period $ 62,000,000 $ 50,000,000