VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - LIHTC Investments - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Variable Interest Entity
Tax credits included in income tax expense	$ 20	$ 17	$ 63	$ 46
Amortization expense included in income tax expense	22	14	67	45
Other tax benefits included in income tax expense	$ 7	$ 2	$ 22	$ 15