SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Collateralized Debt and Loan Obligations (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Collateralized loan obligations (CLOs)
Variable Interest Entity
Carrying value of retained interests	$ 2,766	$ 3,142

The carrying amount (fair value) as of the balance sheet date of the transferor's interests in transferred financial assets (typically securitized receivables, generally not involved in the collection of principal) following transfer of significant portions of such financial instruments to other parties. Such interests could be ancillary cash flows and interest-only strips.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109247956&loc=d3e107314-111719

Name:	us-gaap_InterestsContinuedToBeHeldByTransferorFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant