VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - LIHTC Investments - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Variable Interest Entity
Tax credits included in income tax expense	$ 22	$ 14	$ 43	$ 29
Amortization expense included in income tax expense	22	16	45	31
Other tax benefits included in income tax expense	$ 8	$ 7	$ 15	$ 13