BASIS OF PRESENTATION, UPDATED ACCOUNTING POLICIES AND ACCOUNTING CHANGES - Accounting Changes (Details) - USD ($) $ in Millions		Jun. 30, 2023	Mar. 31, 2023		Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022		Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		$ (17,496)	$ (17,169)		$ (16,974)	$ (15,952)	$ (15,393)		$ (16,455)
Other assets, at fair value		102,972			103,743
Stockholders’ equity		209,422			201,838	199,626
Other liabilities		(79,314)			(87,873)
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			0		352		0		0
Other assets, at fair value					44
Deferred tax assets					106
Other liabilities					39
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders’ equity		199,976	198,353		194,734	191,261	187,962		184,948
Retained earnings | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders’ equity	[1]		0		290		0		0
Accumulated other comprehensive income (loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders’ equity		$ (45,865)	(45,441)		(47,062)	$ (45,495)	(43,585)		(38,765)
Accumulated other comprehensive income (loss) | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders’ equity			$ 0	[1]	$ 27		$ 0	[1]	$ 0

[1] See Note 1 for additional details.