v3.26.1
Fair Value Hierarchy - Summary of Weighted Average of Significant Unobservable Inputs, Loans (Detail)
$ in Millions
Jun. 30, 2026
USD ($)
yr
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
yr
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value $ 4,640   $ 4,905
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value 552 $ 591 546
Corporate      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value 615   326
Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value 302   290
Real estate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value 93   99
Other collateralized      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value 487   855
Other collateralized | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans at fair value $ 131   $ 138
Minimum | Yield | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.063   0.064
Minimum | Yield | Other collateralized | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.062   0.057
Minimum | Recovery rate | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.102   0.325
Minimum | Recovery rate | Real estate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.677   0.690
Minimum | Duration (years) | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input | yr 3.8   3.1
Maximum | Yield | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.174   0.199
Maximum | Yield | Other collateralized | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.064   0.063
Maximum | Recovery rate | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.950   0.949
Maximum | Recovery rate | Real estate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.992   0.992
Maximum | Duration (years) | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input | yr 3.9   4.4
Weighted Average | Yield | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.113   0.180
Weighted Average | Yield | Other collateralized | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.064   0.057
Weighted Average | Recovery rate | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.517   0.654
Weighted Average | Recovery rate | Real estate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input 0.738   0.761
Weighted Average | Duration (years) | Corporate | Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Measurement input | yr 3.8   3.3