SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 336,164	$ 362,025
Gross amounts offset on the Consolidated Balance Sheet	115,888	157,370
Net amounts of assets included on the Consolidated Balance Sheet	220,276	204,655
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	184,850	159,232
Net amounts	35,426	45,423
Deposits paid for securities borrowed
Gross amounts of recognized assets	106,008	96,425
Gross amounts offset on the Consolidated Balance Sheet	11,207	6,358
Net amounts of assets included on the Consolidated Balance Sheet	94,801	90,067
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	20,754	13,474
Net amounts	74,047	76,593
Total
Gross amounts of recognized assets	442,172	458,450
Gross amounts offset on the Consolidated Balance Sheet	127,095	163,728
Net amounts of assets included on the Consolidated Balance Sheet	315,077	294,722
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	205,604	172,706
Net amounts	109,473	122,016
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	313,917	338,564
Gross amounts offset on the Consolidated Balance Sheet	115,888	157,370
Net amounts of liabilities included on the Consolidated Balance Sheet	198,029	181,194
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	102,256	95,563
Net amounts	95,773	85,631
Deposits received for securities loaned
Gross amounts of recognized liabilities	32,346	24,689
Gross amounts offset on the Consolidated Balance Sheet	11,207	6,358
Net amounts of liabilities included on the Consolidated Balance Sheet	21,139	18,331
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	11,085	7,982
Net amounts	10,054	10,349
Total
Gross amounts of recognized liabilities	346,263	363,253
Gross amounts offset on the Consolidated Balance Sheet	127,095	163,728
Net amounts of liabilities included on the Consolidated Balance Sheet	219,168	199,525
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	113,341	103,545
Net amounts	$ 105,827	$ 95,980

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