v3.25.4
Fair Value Hierarchy - Schedule of Level 3 Assets, and Ranges and Weighted Averages of Significant Unobservable Inputs (Detail)
$ in Millions
Dec. 31, 2025
USD ($)
yr
Dec. 31, 2024
USD ($)
yr
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Total financial assets at fair value | $ $ 963,966 $ 907,669
Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Total financial assets at fair value | $ 20,324 20,358
Level 3 | Loans and securities backed by real estate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Total financial assets at fair value | $ $ 155 $ 95
Level 3 | Loans and securities backed by real estate | Minimum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.031 0.072
Level 3 | Loans and securities backed by real estate | Minimum | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.223 0.233
Level 3 | Loans and securities backed by real estate | Minimum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.3 1.9
Level 3 | Loans and securities backed by real estate | Maximum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.451 0.243
Level 3 | Loans and securities backed by real estate | Maximum | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.625 0.692
Level 3 | Loans and securities backed by real estate | Maximum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 9.0 12.1
Level 3 | Loans and securities backed by real estate | Weighted Average | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.106 0.115
Level 3 | Loans and securities backed by real estate | Weighted Average | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.365 0.509
Level 3 | Loans and securities backed by real estate | Weighted Average | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 3.4 3.7
Level 3 | Corporate debt instruments    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Total financial assets at fair value | $ $ 484 $ 728
Level 3 | Corporate debt instruments | Minimum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.021 0.030
Level 3 | Corporate debt instruments | Minimum | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.041 0.068
Level 3 | Corporate debt instruments | Minimum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 2.3 1.6
Level 3 | Corporate debt instruments | Maximum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.180 0.359
Level 3 | Corporate debt instruments | Maximum | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.720 0.690
Level 3 | Corporate debt instruments | Maximum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 14.7 3.3
Level 3 | Corporate debt instruments | Weighted Average | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.080 0.130
Level 3 | Corporate debt instruments | Weighted Average | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.323 0.536
Level 3 | Corporate debt instruments | Weighted Average | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 3.9 2.3
Level 3 | Other    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Total financial assets at fair value | $ $ 265 $ 390
Level 3 | Other | Minimum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.084 0.047
Level 3 | Other | Minimum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.2 1.5
Level 3 | Other | Maximum | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.300 0.379
Level 3 | Other | Maximum | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 8.7 3.5
Level 3 | Other | Weighted Average | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.175 0.152
Level 3 | Other | Weighted Average | Duration (years)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 2.6 2.4