v3.26.1
Fair Value Measurements, Fair Value on a Nonrecurring Basis (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value measurement, nonrecurring, fair value measurement date is different than period end date [true false] true true
Nonrecurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale $ 1,099 $ 2,086
Loans 453 1,257
Equity securities 1,410 2,792
Other assets 39 98
Total assets measured at fair value on a recurring basis 3,001 6,233
Nonrecurring [Member] | Total Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans 420 1,161
Nonrecurring [Member] | Total Consumer [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans 33 96
Nonrecurring [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale 1,086 1,846
Loans 453 1,257
Equity securities 499 1,001
Other assets 39 89
Total assets measured at fair value on a recurring basis 2,077 4,193
Nonrecurring [Member] | Level 2 [Member] | Total Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans 420 1,161
Nonrecurring [Member] | Level 2 [Member] | Total Consumer [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans 33 96
Nonrecurring [Member] | Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale 13 240
Loans 0 0
Equity securities 911 1,791
Other assets 0 9
Total assets measured at fair value on a recurring basis 924 2,040
Nonrecurring [Member] | Level 3 [Member] | Total Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans 0 0
Nonrecurring [Member] | Level 3 [Member] | Total Consumer [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans $ 0 $ 0