DERIVATIVES ACTIVITIES - Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pretax change in accumulated other comprehensive income (loss)
Cash flow hedges expected to be reclassified within 12 months			$ (300)
Maximum length of time hedged in cash flow hedge			10 years
Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	$ 259	$ (69)	$ 336	$ 99
Effective portion of cash flow hedges reclassified from AOCI to earnings	(63)	(114)	(260)	(332)
Interest rate contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	357	(70)	594	153
Effective portion of cash flow hedges reclassified from AOCI to earnings	(28)	(84)	(148)	(218)
Foreign exchange contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	(98)	1	(258)	(56)
Effective portion of cash flow hedges reclassified from AOCI to earnings	(35)	(30)	(112)	(114)
Credit derivatives | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	$ 0	$ 0	$ 0	$ 2