SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities purchased under agreements to resell	$ 266,192	$ 267,319
Deposits paid for securities borrowed	78,090	78,408
Total, net	344,282	345,727
Allowance for credit losses on securities purchased and borrowed	(18)	(27)
Total, net of allowance	344,264	345,700
Securities sold under agreements to repurchase	288,746	264,958
Deposits received for securities loaned	10,641	13,149
Total, net	299,387	278,107
Securities-for-securities lending transactions	$ 4,100	$ 4,300