SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	$ 297,163	$ 253,514
Deposits received for securities loaned	12,272	11,678
Total	309,435	265,192
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	114,492	86,785
Deposits received for securities loaned	0	41
Total	114,492	86,826
State and municipal securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	2,226	2,605
Deposits received for securities loaned	11	0
Total	2,237	2,605
Foreign government
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	110,796	99,131
Deposits received for securities loaned	269	179
Total	111,065	99,310
Corporate bonds
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	21,909	21,719
Deposits received for securities loaned	597	749
Total	22,506	22,468
Equity securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	17,919	12,920
Deposits received for securities loaned	10,677	10,664
Total	28,596	23,584
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	18,541	19,421
Deposits received for securities loaned	0	0
Total	18,541	19,421
Asset-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	6,540	6,207
Deposits received for securities loaned	0	0
Total	6,540	6,207
Other
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	4,740	4,726
Deposits received for securities loaned	718	45
Total	5,458	4,771
Open and overnight
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	152,704	108,405
Deposits received for securities loaned	7,576	6,296
Total	160,280	114,701
Up to 30 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	69,173	70,850
Deposits received for securities loaned	155	774
Total	69,328	71,624
31–90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	34,516	29,898
Deposits received for securities loaned	2,359	2,626
Total	36,875	32,524
Greater than 90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	40,770	44,361
Deposits received for securities loaned	2,182	1,982
Total	$ 42,952	$ 46,343