v3.26.1
Commitments and Contingencies - Narrative (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Loss Contingencies [Line Items]    
Pledged Collateral $ 2,473 $ 2,467
Possible losses in excess of amounts accrued 25  
Potential future loss 98  
Federal Home Loan Bank | Line of Credit    
Loss Contingencies [Line Items]    
Non-putable funding agreements issued to FHLB 1,850 1,700
FABNTrustMember | Line of Credit    
Loss Contingencies [Line Items]    
Non-putable funding agreements issued to FHLB 406 $ 400
Acquisition of mortgage loans    
Loss Contingencies [Line Items]    
Amount of purchase commitments 93  
Purchase of limited partnership and private placement investments    
Loss Contingencies [Line Items]    
Amount of purchase commitments 2,431  
Purchase of limited partnership and private placement investments | VOEs    
Loss Contingencies [Line Items]    
Amount of purchase commitments $ 359