COMMITMENTS AND CONTINGENCIES - Schedule of Outstanding Off-balance sheet Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Commitments [Line Items]
Commitment amount	$ 58,265	$ 58,435
Undrawn commitments to extend credit
Other Commitments [Line Items]
Commitment amount	55,887	55,899
Financial standby letters of credit
Other Commitments [Line Items]
Commitment amount	2,181	2,315
Performance letters of credit
Other Commitments [Line Items]
Commitment amount	55	65
Commercial letters of credit
Other Commitments [Line Items]
Commitment amount	59	75
Marketing rights
Other Commitments [Line Items]
Commitment amount	49	51
Risk participation agreements
Other Commitments [Line Items]
Commitment amount	22	19
Residential mortgage loans sold with recourse
Other Commitments [Line Items]
Commitment amount	$ 12	$ 11