Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUES OF ASSETS AND LIABILITIES - Level 3 Classification of Gains/Losses (Details)

v3.10.0.1
FAIR VALUES OF ASSETS AND LIABILITIES - Level 3 Classification of Gains/Losses (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings     $ 16 $ 8
MSRs        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings $ (1) $ 0 0 (1)
Mortgage banking income 1 0    
Securities gains (losses) 0 0    
Other expense 0      
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings (1) 0    
Fair Value Assets Measured On Recurring Basis Gain Loss Included In Noninterest income   0    
Derivative Financial Instruments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Mortgage banking income (10) (2)    
Securities gains (losses) 0 0    
Other expense 0      
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings (10) (2)    
Fair Value Assets Measured On Recurring Basis Gain Loss Included In Noninterest income   0    
Municipal securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings (1) (1) (2) (3)
Mortgage banking income 0 0    
Securities gains (losses) 0 (1)    
Other expense (1)   (2)  
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings 1 1    
Fair Value Assets Measured On Recurring Basis Gain Loss Included In Noninterest income   0    
Asset-backed securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings   (3) (2) (3)
Mortgage banking income   0    
Securities gains (losses)   (3)    
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings   3    
Fair Value Assets Measured On Recurring Basis Gain Loss Included In Noninterest income   0    
Automobile        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings 0 2 0 1
Mortgage banking income 0 0    
Securities gains (losses) 0 0    
Other expense 0      
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings $ 0 (2)    
Mortgage Banking Income [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings     16 8
Mortgage Banking Income [Member] | MSRs        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 (1)
Mortgage Banking Income [Member] | Municipal securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 0
Mortgage Banking Income [Member] | Asset-backed securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 0
Mortgage Banking Income [Member] | Automobile        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 0
Securities Gain (Losses) [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings     0 0
Securities Gain (Losses) [Member] | MSRs        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 0
Securities Gain (Losses) [Member] | Municipal securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     0 (3)
Securities Gain (Losses) [Member] | Asset-backed securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     (2) (3)
Securities Gain (Losses) [Member] | Automobile        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings     $ 0 0
Noninterest Income        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings       0
Noninterest Income | MSRs        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings       0
Noninterest Income | Municipal securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings       0
Noninterest Income | Asset-backed securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings       0
Noninterest Income | Automobile        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings   $ 2   $ 1