SUPPLEMENTAL INFORMATION - Schedule of Fair Value of Derivatives, Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Liabilities	$ 2,511	$ 4,883
Gross accrued interest	(13)	(24)
Gross derivatives recognized in statement of financial position	2,497	4,859
Amounts offset in statement of financial position
Netting adjustments	(1,605)	(3,094)
Cash collateral	(462)	(1,355)
Amounts offset in statement of financial position	(2,066)	(4,449)
Net derivatives	431	410
Securities held as collateral	0	0
Net amount	431	410
Derivatives accounted for as hedges
Offsetting Liabilities [Line Items]
Liabilities	269	834
Derivatives accounted for as hedges | Other contracts
Offsetting Liabilities [Line Items]
Liabilities	0	0
Derivatives accounted for as hedges | Interest rate contracts
Offsetting Liabilities [Line Items]
Liabilities	109	210
Derivatives accounted for as hedges | Currency exchange contracts
Offsetting Liabilities [Line Items]
Liabilities	160	624
Derivatives not accounted for as hedges
Offsetting Liabilities [Line Items]
Liabilities	2,242	4,048
Derivatives not accounted for as hedges | Other contracts
Offsetting Liabilities [Line Items]
Liabilities	34	17
Derivatives not accounted for as hedges | Interest rate contracts
Offsetting Liabilities [Line Items]
Liabilities	10	20
Derivatives not accounted for as hedges | Currency exchange contracts
Offsetting Liabilities [Line Items]
Liabilities	$ 2,199	$ 4,011