DERIVATIVES ACTIVITIES - Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pretax change in accumulated other comprehensive income (loss)
Cash flow hedges expected to be reclassified within 12 months			$ (400)
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	$ 7	$ 104	$ 77	$ 168
Effective portion of cash flow hedges reclassified from AOCI to earnings	(111)	(101)	(197)	(218)
Interest rate contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	17	155	237	223
Effective portion of cash flow hedges reclassified from AOCI to earnings	(74)	(73)	(120)	(134)
Foreign exchange contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	(10)	(51)	(160)	(57)
Effective portion of cash flow hedges reclassified from AOCI to earnings	(37)	(28)	(77)	(84)
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