Securities Financing Activities - Schedule of secured financing transactions by assets pledged & remaining maturity (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	$ 541,587	$ 398,218
Securities loaned and other	33,700	27,228
Overnight and continuous
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	247,579	142,185
Securities loaned and other	28,402	22,876
Up to 30 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	174,971	180,674
Securities loaned and other	997	375
30 – 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	71,637	41,611
Securities loaned and other	2,132	2,328
Greater than 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	47,400	33,748
Securities loaned and other	2,169	1,649
Mortgage-backed securities, U.S. government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	28,811	13,100
Securities loaned and other	0	0
Mortgage-backed securities, Residential - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	2,165	2,972
Securities loaned and other	0	0
Mortgage-backed securities, Commercial - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,390	1,594
Securities loaned and other	0	0
U.S. Treasury and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	323,078	177,581
Securities loaned and other	69	14
Obligations of U.S. states and municipalities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,150	1,557
Securities loaned and other	0	0
Non-U.S. government debt
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	154,900	170,196
Securities loaned and other	4,313	2,485
Corporate debt securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	13,898	14,231
Securities loaned and other	428	287
Asset-backed securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	3,867	3,508
Securities loaned and other	0	0
Equity securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	12,328	13,479
Securities loaned and other	$ 28,890	$ 24,442

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- Definition

Amount, before effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

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