NONINTEREST INCOME - Noninterest Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Income and Expenses [Abstract]
Revenue from contracts with customers	[1]	$ 1,119
Revenue from other sources		477
Total noninterest income		$ 1,596	$ 1,534	$ 1,497

[1] There is no revenue from contracts with customers included in Other non-segment operations.