v3.25.2
Fair Value Measurements - Quantitative Information about Nonrecurring Fair Value Measurement of Assets and Liabilities Classified as Level 3 (Detail) - Fair Value, Nonrecurring
$ in Millions
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis $ 605 $ 450
Commercial loans held for sale    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis   0
Commercial Loans    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis 509 350
Level 3    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis 509 350
Level 3 | Commercial loans held for sale    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis   0
Level 3 | Commercial Loans    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Total assets at fair value on a non-recurring basis $ 509 $ 350
Loss severity rates | Level 3 | Commercial Loans | Minimum | Valuation of third-party appraisal on underlying collateral    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Range of Inputs 0.04 0.08
Loss severity rates | Level 3 | Commercial Loans | Maximum | Valuation of third-party appraisal on underlying collateral    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Range of Inputs 1 1
Loss severity rates | Level 3 | Commercial Loans | Weighted Average | Valuation of third-party appraisal on underlying collateral    
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]    
Range of Inputs 0.29 0.26