GOODWILL AND INTANGIBLE ASSETS - Changes in Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Finite and Indefinite-lived Intangible Assets
Beginning balance	$ 3,763
Acquisitions/renewals/ divestitures	295
Amortization	(99)
Impairments	0
FX translation and other	15
Ending balance	3,974
Mortgage servicing rights (MSRs)	658	$ 665
Total intangible assets	4,632	$ 4,428
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Beginning balance	192
Acquisitions/renewals/ divestitures	0
Amortization	0
Impairments	0
FX translation and other	15
Ending balance	207
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Beginning balance	1,087
Acquisitions/renewals/ divestitures	0
Amortization	(38)
Impairments	0
FX translation and other	0
Ending balance	1,049
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Beginning balance	2,385
Acquisitions/renewals/ divestitures	290
Amortization	(47)
Impairments	0
FX translation and other	0
Ending balance	2,628
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Beginning balance	90
Acquisitions/renewals/ divestitures	5
Amortization	(6)
Impairments	0
FX translation and other	0
Ending balance	89
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Beginning balance	1
Acquisitions/renewals/ divestitures	0
Amortization	0
Impairments	0
FX translation and other	0
Ending balance	1
Other
Finite and Indefinite-lived Intangible Assets
Beginning balance	8
Acquisitions/renewals/ divestitures	0
Amortization	(8)
Impairments	0
FX translation and other	0
Ending balance	$ 0