OTHER OPERATING EXPENSE (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Deposit insurance	$ 137	$ 120	$ 115
Promotional expense	105	98	101
Settlements and operating losses	54	62	43
Other	251	246	271
Other operating expense	$ 547	$ 526	$ 530