SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	$ 337,292	$ 266,564
Deposits received for securities loaned	15,964	19,774
Total	353,256	286,338
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	127,237	100,781
Deposits received for securities loaned	0	27
Total	127,237	100,808
State and municipal
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	1,117	1,938
Deposits received for securities loaned	1	5
Total	1,118	1,943
Foreign government
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	123,451	95,880
Deposits received for securities loaned	192	272
Total	123,643	96,152
Corporate bonds
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	20,922	18,761
Deposits received for securities loaned	349	249
Total	21,271	19,010
Equity securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	11,617	12,010
Deposits received for securities loaned	14,652	19,069
Total	26,269	31,079
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	42,762	28,458
Deposits received for securities loaned	0	0
Total	42,762	28,458
Asset-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	3,925	4,873
Deposits received for securities loaned	0	0
Total	3,925	4,873
Other
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	6,261	3,863
Deposits received for securities loaned	770	152
Total	7,031	4,015
Open and overnight
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	175,461	108,534
Deposits received for securities loaned	12,412	15,758
Total	187,873	124,292
Up to 30 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	87,421	82,749
Deposits received for securities loaned	190	208
Total	87,611	82,957
31–90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	39,723	35,108
Deposits received for securities loaned	1,299	1,789
Total	41,022	36,897
Greater than 90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	34,687	40,173
Deposits received for securities loaned	2,063	2,019
Total	$ 36,750	$ 42,192