Variable Interest Entities and Securitization Activities (Transfers of Assets with Continuing Involvement 2) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity
Derivative assets	$ 29,173	$ 30,813
Derivative liabilities	27,258	26,695
SPE
Variable Interest Entity
Retained interests	2,019	988
Interests purchased in the secondary market (fair value)	299	619
Derivative assets	216	227
Derivative liabilities	178	85
SPE \| Investment Grade
Variable Interest Entity
Retained interests	1,593	411
Interests purchased in the secondary market (fair value)	200	533
SPE \| Non-investment Grade
Variable Interest Entity
Retained interests	426	577
Interests purchased in the secondary market (fair value)	99	86
SPE \| Level 2
Variable Interest Entity
Retained interests	1,754	429
Interests purchased in the secondary market (fair value)	276	588
Derivative assets	121	78
Derivative liabilities	175	81
SPE \| Level 2 \| Investment Grade
Variable Interest Entity
Retained interests	1,580	407
Interests purchased in the secondary market (fair value)	193	531
SPE \| Level 2 \| Non-investment Grade
Variable Interest Entity
Retained interests	174	22
Interests purchased in the secondary market (fair value)	83	57
SPE \| Level 3
Variable Interest Entity
Retained interests	265	559
Interests purchased in the secondary market (fair value)	23	31
Derivative assets	95	149
Derivative liabilities	3	4
SPE \| Level 3 \| Investment Grade
Variable Interest Entity
Retained interests	13	4
Interests purchased in the secondary market (fair value)	7	2
SPE \| Level 3 \| Non-investment Grade
Variable Interest Entity
Retained interests	252	555
Interests purchased in the secondary market (fair value)	$ 16	$ 29

Fair value of interests purchased in the secondary market

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets 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 210
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-Name Accounting Standards Codification
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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. 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 210
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-URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313

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- Definition

Fair value portion of interest continued to be held by a transferor after transferring financial assets to a third party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
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+ References

No definition available.

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