SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
MSR fees
Servicing fees, location	Commissions and fees	Commissions and fees	Commissions and fees
Mortgage servicing rights
Classification of Securitizations
Principal amount of loans and other financial instruments	$ 56,000.0	$ 52,000.0
MSR fees
Servicing fees	127.0	129.0	$ 122.0
Late fees	1.0	4.0	4.0
Total MSR fees	128.0	133.0	126.0
Mortgage securitizations - Non-agency-sponsored
Classification of Securitizations
Principal securitized	9,400.0	4,800.0	13,900.0
Proceeds from new securitizations	8,800.0	3,500.0	$ 13,400.0
Mortgage-backed securities - U.S. agency-sponsored
Re-securitizations
Securities transferred to re-securitization entities	22,800.0	17,100.0
Fair value of re-securitizations deals in which the entity holds a retained interest	1,600.0	1,700.0
Market value of retained interest related to re-securitization transaction	977.0	930.0
Original fair value of re-securitizations deals in which the entity holds a retained interest	76,800.0	84,100.0
Consumer
Classification of Securitizations
Principal securitized	1,200.0	1,000.0
Proceeds from new securitizations	1,200.0	700.0
Gains recognized on the securitization	$ 5.1	$ 7.5

No definition available.

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- Definition

Continuing Involvement with Transferred Financial Assets, Principal Amount Securitized During Period

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No definition available.

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- Definition

Represents the fair value of re-securitizations deals in which entity holds retained interest.

+ References

No definition available.

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- Definition

This element represents the amount of market value of interest owned by the entity in private-label re-securitization entities, for current period.

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No definition available.

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Represents the amount of original fair value of re-securitizations deals in which the entity holds a retained interest.

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No definition available.

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- Definition

Re-securitizations [Abstract]

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No definition available.

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- Definition

Represents the amount of securities transferred to re-securitization entities.

+ References

No definition available.

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- Definition

Cash Flows between a transferor and a transferee attributable to newly transferred assets related to either a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

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- Definition

Indicates line item in statement of income or comprehensive income that includes contractually specified servicing fee income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

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- Definition

All amounts that, per contract, are due to the servicer in exchange for servicing the financial asset and would no longer be received by a servicer if the beneficial owners of the serviced assets (or their trustees or agents) were to exercise their actual or potential authority under the contract to shift the servicing to another servicer. Depending on the servicing contract, those fees may include some or all of the difference between the interest rate collected on the asset being serviced and the rate to be paid to the beneficial owners of the asset.

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- Definition

Income from mortgage banking activities (fees and commissions) and servicing real estate mortgages, credit cards, and other financial assets held by others net of any related impairment of capitalized service costs. Also includes any premiums received in lieu of regular servicing fees on such loans only as earned over the life of the loans.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph b
-Subparagraph (1)
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph b
-Subparagraph (1)(Instruction 3)
-Publisher SEC

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- Definition

A gain (loss) realized on a transfer, accounted for as a sale, of all or a portion of financial assets in which the transferor surrenders control and receives consideration other than a beneficial interest in the assets transferred. Reflects the amount of sales proceeds in excess of, or deficient from, the sum of the carrying amounts of transferred financial assets plus transaction costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

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- Definition

All amounts that are due to the servicer of a financial asset as a result of the debt holder not meeting the monthly payment terms.

+ References

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- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that continue to be recognized in the statement of financial position. Includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

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