SUPPLEMENTAL INFORMATION - Schedule of Fair Value of Derivatives, Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Liabilities	$ 2,453	$ 4,883
Gross accrued interest	0	(24)
Gross derivatives recognized in statement of financial position	2,454	4,859
Amounts offset in statement of financial position
Netting adjustments	(1,802)	(3,094)
Cash collateral	(276)	(1,355)
Amounts offset in statement of financial position	(2,078)	(4,449)
Net derivatives	376	410
Securities held as collateral	0	0
Net amount	376	410
Derivatives accounted for as hedges
Offsetting Liabilities [Line Items]
Liabilities	213	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	108	210
Derivatives accounted for as hedges | Currency exchange contracts
Offsetting Liabilities [Line Items]
Liabilities	105	624
Derivatives not accounted for as hedges
Offsetting Liabilities [Line Items]
Liabilities	2,240	4,048
Derivatives not accounted for as hedges | Other contracts
Offsetting Liabilities [Line Items]
Liabilities	46	17
Derivatives not accounted for as hedges | Interest rate contracts
Offsetting Liabilities [Line Items]
Liabilities	6	20
Derivatives not accounted for as hedges | Currency exchange contracts
Offsetting Liabilities [Line Items]
Liabilities	$ 2,187	$ 4,011