OTHER OPERATING EXPENSE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Income and Expenses [Abstract]
Deposit insurance	$ 28	$ 36	$ 59	$ 68
Promotional expense	34	29	59	55
Settlements and operating losses	12	12	24	25
Other	53	71	105	124
Other operating expense	$ 127	$ 148	$ 247	$ 272