VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - LIHTC Investments - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Variable Interest Entity
Tax credits included in income tax expense	$ 34	$ 26	$ 69	$ 51
Amortization expense included in income tax expense	35	28	72	55
Other tax benefits included in income tax expense	$ 8	$ 6	$ 16	$ 12