Securities Financing Activities - Types of Financial Assets Pledged and Remaining Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	$ 480,097	$ 398,218
Securities loaned and other	35,520	27,228
Lending transactions	16,435	18,414
Securities-for-securities
Securities Financing Transaction [Line Items]
Lending transactions	6,600	9,200
Overnight and continuous
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	190,179	166,425
Securities loaned and other	28,747	22,876
Up to 30 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	176,526	156,434
Securities loaned and other	869	375
30 – 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	53,653	41,611
Securities loaned and other	3,324	2,328
Greater than 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	59,739	33,748
Securities loaned and other	2,580	1,649
Mortgage-backed securities, U.S. government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	19,277	13,100
Securities loaned and other	0	0
Mortgage-backed securities, Residential - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	2,337	2,972
Securities loaned and other	0	0
Mortgage-backed securities, Commercial - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,415	1,594
Securities loaned and other	0	0
U.S. Treasury and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	226,381	177,581
Securities loaned and other	250	14
Obligations of U.S. states and municipalities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	405	1,557
Securities loaned and other	0	0
Non-U.S. government debt
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	197,813	170,196
Securities loaned and other	1,481	2,485
Corporate debt securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	14,390	14,231
Securities loaned and other	194	287
Asset-backed securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	3,320	3,508
Securities loaned and other	0	0
Equity securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	14,759	13,479
Securities loaned and other	$ 33,595	$ 24,442

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 405
-Section 55
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35710563&loc=d3e44140-110984

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64858031&loc=SL6224234-111729

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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

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