SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Loan Delinquencies and Liquidation Losses (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Mortgage securitizations - Non-agency-sponsored
Variable Interest Entity
Securitized assets past due	$ 40,800.0	$ 30,700.0
Securitized assets liquidation losses	26.2	49.0
Mortgage securitizations - Non-agency-sponsored \| 90 days past due
Variable Interest Entity
Securitized assets past due	500.0	400.0
Mortgage-backed securities - Residential
Variable Interest Entity
Securitized assets past due	16,900.0	11,700.0
Securitized assets liquidation losses	26.2	49.0
Mortgage-backed securities - Residential \| 90 days past due
Variable Interest Entity
Securitized assets past due	500.0	400.0
Mortgage-backed securities - Commercial
Variable Interest Entity
Securitized assets past due	23,900.0	19,000.0
Securitized assets liquidation losses	0.0	0.0
Mortgage-backed securities - Commercial \| 90 days past due
Variable Interest Entity
Securitized assets past due	0.0	$ 0.0
Personal loan
Variable Interest Entity
Securitized assets past due	$ 200.0

This is the principal amount of loans (across all types of loans) that are overdue in payment by a set number of days.

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 (e)(4)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

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- Definition

Amount of credit loss after recoveries for transferred financial assets that continue to be recognized in the statement of financial position.

+ References

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 (e)(5)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

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- Definition

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+ References

No definition available.

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