v3.26.1
Derivative Instruments and Hedging Activities - Narrative (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Dec. 22, 2025
Jun. 28, 2024
Derivative [Line Items]        
Loss protection fee percentage     4.94% 7.95%
Reclaim cash collateral $ 34 $ 36    
Obligation to return cash collateral 122 $ 62    
Interest Rate Swap | Financial Institution Counterparties        
Derivative [Line Items]        
Notional amount $ 1,100      
Credit Default Swap | Residential Real Estate        
Derivative [Line Items]        
Notional amount     $ 80 $ 1,700
Credit Default Swap | Derivatives Not Designated as Hedging Instruments        
Derivative [Line Items]        
Notional amount     $ 80 $ 87
Derivative, notional amount, percent of reference pool     12.50% 5.00%
Credit Default Swap, Buying Protection | Derivatives Not Designated as Hedging Instruments        
Derivative [Line Items]        
Notional amount       $ 87