Quarterly report pursuant to Section 13 or 15(d)

AVAILABLE-FOR-SALE SECURITIES - Narrative (Details)

v3.8.0.1
AVAILABLE-FOR-SALE SECURITIES - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]      
Held To Maturity Securities Transferred To Available For Sale $ 3,000    
Available For Sale Securities Transferred To Held To Maturity Securities 3,000    
Pledged investment securities to secure public and trust deposits, trading account liabilities, US Treasury demand notes and security repurchase agreements 7,000   $ 6,000
Unrealized Net Gains Recognized In OCI At Time Of Transfer Of Available For Sale Securities Transferred To Held To Maturity Securities 26    
Unrealized Net Losses Recognized In OCI At Time Of Transfer Of Available For Sale Securities Transferred To Held To Maturity Securities 56    
Commercial      
Schedule of Available-for-sale Securities [Line Items]      
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset $ 3 $ 3