SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements by Class of Collateral (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Assets Sold under Agreements to Repurchase
Repurchase agreements	$ 304,310	$ 305,597
Securities lending agreements	31,454	33,029
Total	335,764	338,626
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	102,415	85,861
Securities lending agreements	132	90
Total	102,547	85,951
State and municipal securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	893	1,053
Securities lending agreements	0	0
Total	893	1,053
Foreign government securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	121,092	133,352
Securities lending agreements	185	212
Total	121,277	133,564
Corporate bonds
Assets Sold under Agreements to Repurchase
Repurchase agreements	23,112	20,398
Securities lending agreements	187	152
Total	23,299	20,550
Equity securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	22,182	25,653
Securities lending agreements	30,663	32,517
Total	52,845	58,170
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	26,263	33,573
Securities lending agreements	0	0
Total	26,263	33,573
Asset-backed securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	1,654	1,681
Securities lending agreements	0	0
Total	1,654	1,681
Other
Assets Sold under Agreements to Repurchase
Repurchase agreements	6,699	4,026
Securities lending agreements	287	58
Total	$ 6,986	$ 4,084