Derivative Financial Instruments and Hedging Activities - Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Fair value of assets (liabilities) available for offset	$ 353	$ 320
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	107,601	113,871
Derivative asset, Fair value	662	502
Collateral available for netting	140	451
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	583	869
Cash held	162	30
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Other Assets [Member] \| Interest Rate Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	13,046	9,533
Derivative asset, Fair value	353	42
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Other Assets [Member] \| Foreign Currency Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	1,822	1,829
Derivative asset, Fair value	37	37
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Other Liabilities [Member] \| Interest Rate Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	38	231
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Other Liabilities [Member] \| Foreign Currency Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	61	60
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Other Assets [Member] \| Interest Rate Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	504	768
Derivative asset, Fair value	2	8
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Other Assets [Member] \| Foreign Currency Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	3,317	2,075
Derivative asset, Fair value	30	43
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Other Liabilities [Member] \| Interest Rate Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	2	0
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Other Liabilities [Member] \| Foreign Currency Swaps [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	104	58
Not Designated as Hedging Instrument [Member] \| Other Assets [Member] \| Interest Rate Contracts [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	88,912	99,666
Derivative asset, Fair value	240	372
Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member] \| Interest Rate Contracts [Member] \| Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, Fair value	$ 378	$ 520

Derivative Assets (Liabilities), Net, Fair Value, Amount Not Offset Against Collateral

No definition available.

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- Definition

Nominal or face amount used to calculate payments on the derivative asset.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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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.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements offset against derivative liabilities.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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