FAIR VALUE MEASUREMENTS - Schedule of Assets Measured on Recurring Basis Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1,411	$ 902	$ 1,029	$ 658
Issuances	70	109	244	318
Purchases	0
Acquisitions			16
Settlements	(31)	(54)	(102)	(159)
Change in fair value during the period recognized in earnings	74	21	337	161
Ending balance	1,524	978	1,524	978
Other Derivative Contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11	89	38	197
Issuances	20	81	84	323
Acquisitions	0		0
Settlements	2	(104)	134	(283)
Change in fair value during the period recognized in earnings	(66)	(13)	(289)	(184)
Ending balance	$ (33)	$ 53	$ (33)	$ 53

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Acquired

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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- Definition

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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