v3.25.4
Fair Value Measurements (Summary Of Quantitative Information About Level 3 Fair Value Measurements) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Level 3 [Member] | Residential Mortgage    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Assets, Fair Value Disclosure $ 970 $ 1,007
Level 3 [Member] | Commercial Real Estate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Assets, Fair Value Disclosure $ 93 $ 97
Recurring Fair Value Measurements | Minimum [Member] | Discounted Cash Flow [Member] | Residential Mortgage    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.042 0.046
Option-Adjusted Spread 4.70% 4.80%
Recurring Fair Value Measurements | Minimum [Member] | Discounted Cash Flow [Member] | Commercial Real Estate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.065 0.054
Measurement Input, Discount Rate 8.00% 7.00%
Recurring Fair Value Measurements | Maximum [Member] | Discounted Cash Flow [Member] | Residential Mortgage    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.169 0.231
Option-Adjusted Spread 8.00% 7.70%
Recurring Fair Value Measurements | Maximum [Member] | Discounted Cash Flow [Member] | Commercial Real Estate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.076 0.106
Measurement Input, Discount Rate 10.00% 8.00%
Recurring Fair Value Measurements | Weighted Average [Member] | Discounted Cash Flow [Member] | Residential Mortgage    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.075 0.080
Option-Adjusted Spread 5.00% 5.10%
Recurring Fair Value Measurements | Weighted Average [Member] | Discounted Cash Flow [Member] | Commercial Real Estate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average CPR 0.075 0.077
Measurement Input, Discount Rate 8.20% 7.10%