ALLOWANCE FOR CREDIT LOSSES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Loans and Leases Receivable, Allowance [Abstract]
Reduction of allowance for loan and leases losses due to loans sold or transferred to held-for-sale or to discontinued operations	$ 148	$ 1,000
Reduction of allowance for loan and leases losses due to transfer to real estate loan portfolio	29	281
Decrease (increase) of allowance related to foreign currency translation	$ (63)	$ 145

Amount of gain (loss) from converting allowance reserve for credit loss to currency of reporting entity from amount denominated or measured in a different currency.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Foreign Currency Translation
-URI http://asc.fasb.org/extlink&oid=6513664

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_AllowanceForLoanAndLeaseLossesForeignCurrencyTranslation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration