v3.25.2
Mortgage Servicing Rights - MSRs and Related Characteristics by Portfolio (Detail) - USD ($)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Servicing Assets at Fair Value [Line Items]            
Fair value $ 3,305 $ 3,369 $ 3,312 $ 3,326 $ 3,462 $ 3,377
MSR portfolio            
Servicing Assets at Fair Value [Line Items]            
Servicing portfolio 215,860 216,374        
Fair value $ 3,305 $ 3,369        
Value (bps) 1.53% 1.56%        
Weighted-average servicing fees (bps) 0.30% 0.30%        
Multiple (value/servicing fees) 5.09 5.17        
Weighted-average note rate 4.29% 4.18%        
Weighted-average age (in years) 5 years 3 months 18 days 5 years        
Weighted-average expected prepayment (constant prepayment rate) 8.90% 8.60%        
Weighted-average expected life (in years) 7 years 3 months 18 days 7 years 4 months 24 days        
Weighted-average option adjusted spread 5.90% 5.70%        
MSR portfolio | HFA            
Servicing Assets at Fair Value [Line Items]            
Servicing portfolio $ 54,999 $ 52,807        
Fair value $ 834 $ 856        
Value (bps) 1.52% 1.62%        
Weighted-average servicing fees (bps) 0.35% 0.35%        
Multiple (value/servicing fees) 4.29 4.57        
Weighted-average note rate 5.05% 4.92%        
Weighted-average age (in years) 4 years 7 months 6 days 4 years 6 months        
Weighted-average expected prepayment (constant prepayment rate) 10.00% 9.90%        
Weighted-average expected life (in years) 7 years 6 months 7 years 6 months        
Weighted-average option adjusted spread 7.40% 5.80%        
MSR portfolio | Government            
Servicing Assets at Fair Value [Line Items]            
Servicing portfolio $ 24,371 $ 25,139        
Fair value $ 481 $ 512        
Value (bps) 1.97% 2.04%        
Weighted-average servicing fees (bps) 0.45% 0.45%        
Multiple (value/servicing fees) 4.42 4.56        
Weighted-average note rate 4.38% 4.35%        
Weighted-average age (in years) 6 years 6 months 6 years 1 month 6 days        
Weighted-average expected prepayment (constant prepayment rate) 10.40% 10.20%        
Weighted-average expected life (in years) 6 years 8 months 12 days 6 years 9 months 18 days        
Weighted-average option adjusted spread 6.60% 6.20%        
MSR portfolio | Conventional            
Servicing Assets at Fair Value [Line Items]            
Servicing portfolio $ 136,490 $ 138,428        
Fair value $ 1,990 $ 2,001        
Value (bps) 1.46% 1.45%        
Weighted-average servicing fees (bps) 0.25% 0.25%        
Multiple (value/servicing fees) 5.75 5.69        
Weighted-average note rate 3.96% 3.87%        
Weighted-average age (in years) 5 years 3 months 18 days 5 years        
Weighted-average expected prepayment (constant prepayment rate) 8.20% 7.80%        
Weighted-average expected life (in years) 7 years 3 months 18 days 7 years 4 months 24 days        
Weighted-average option adjusted spread 5.10% 5.60%