v3.26.1
Fair Value Disclosures - Quantitative Information about Recurring Level 3 Fair Value Measurements (Details)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Mortgage Loans [Abstract]    
Mortgage loans FVO held-for-investment $ 6,906 $ 7,005
Other assets, fair value 6,294 6,421
Fair Value, Measurements, Recurring    
Mortgage Loans [Abstract]    
Mortgage loans FVO held-for-investment 6,906 7,005
Other assets, fair value 6,294 6,421
Total Assets carried at fair value on a recurring basis 89,139 98,838
Liabilities [Abstract]    
Total liabilities carried at fair value on a recurring basis 7,143 6,817
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Mortgage Loans [Abstract]    
Mortgage loans FVO held-for-investment 716 1,418
Other assets, fair value 4,793 5,029
Total Assets carried at fair value on a recurring basis 8,834 9,933
Liabilities [Abstract]    
Total liabilities carried at fair value on a recurring basis 198 155
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Discounted Cash Flows    
Mortgage Loans [Abstract]    
Other assets, fair value 4,197 4,424
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Price    
Assets [Abstract]    
Debt Securities 2,402 2,532
Mortgage Loans [Abstract]    
Mortgage loans FVO held-for-investment 716 1,418
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Valuation Techniques    
Assets [Abstract]    
Debt Securities 923 954
Mortgage Loans [Abstract]    
Other assets, fair value $ 596 $ 605
Fair Value, Measurements, Recurring | Investments securities | Fair Value, Inputs, Level 3 | Weighted Average | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 77.2 82.1
Fair Value, Measurements, Recurring | Investments securities | Fair Value, Inputs, Level 3 | Minimum | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 0.0 0.0
Fair Value, Measurements, Recurring | Investments securities | Fair Value, Inputs, Level 3 | Maximum | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 3,138.1 3,520.6
Fair Value, Measurements, Recurring | Mortgage loans held-for-investment | Fair Value, Inputs, Level 3 | Weighted Average | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 83.2 89.0
Fair Value, Measurements, Recurring | Mortgage loans held-for-investment | Fair Value, Inputs, Level 3 | Minimum | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 25.3 48.4
Fair Value, Measurements, Recurring | Mortgage loans held-for-investment | Fair Value, Inputs, Level 3 | Maximum | Price    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
External Pricing Source(s) 104.9 105.8
Fair Value, Measurements, Recurring | Other Asset Fair Value | Fair Value, Inputs, Level 3 | Weighted Average | Discounted Cash Flows    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
OAS 0.49% 0.50%
Fair Value, Measurements, Recurring | Other Asset Fair Value | Fair Value, Inputs, Level 3 | Minimum | Discounted Cash Flows    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
OAS 0.20% 0.17%
Fair Value, Measurements, Recurring | Other Asset Fair Value | Fair Value, Inputs, Level 3 | Maximum | Discounted Cash Flows    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
OAS 8.40% 88.50%