BUSINESS OPERATING SEGMENTS - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($) segment
Segment Reporting Information [Line Items]
Number of segments | segment	2
Consumer Banking | Maximum
Segment Reporting Information [Line Items]
Customer revenue targets	$ 25
Commercial Banking | Minimum
Segment Reporting Information [Line Items]
Customer revenue targets	25
Commercial Banking | Maximum
Segment Reporting Information [Line Items]
Customer revenue targets	$ 2,500