VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - LIHTC Investments - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Variable Interest Entity
Tax credits included in income tax expense	$ 35	$ 25
Amortization expense included in income tax expense	37	27
Other tax benefits included in income tax expense	$ 8	$ 6