v3.25.1
Fair Value Measurements - Narrative (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Unfunded commitments, equity securities measured at net asset value $ 20   $ 20
Revaluation period 90 days    
Deferred fee income $ 7   3
Unfunded Loan Commitment      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Deferred fee income 157   $ 168
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Transfers Out of Level 3 604 $ 135  
Transfers Into Level 3 (346) (13)  
Level 3 | Equity contracts - bilateral OTC(2)      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Derivatives, net, Transfers out of Level 3 42 (9)  
Level 3 | Long-term debt      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Transfers Out of Level 3 538 128  
Transfers Into Level 3 (278) (13)  
Level 3 | Deposits      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Transfers Out of Level 3 66 7  
Transfers Into Level 3 $ (68) $ 0