Derivative Financial Instruments Credit Derivative Instruments - TRS Contracts (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Credit Derivative Instruments - TRS Contracts [Line Items]
Derivative, Notional Amount	$ 261,398	$ 233,052
Derivative Asset, Fair Value, Gross Asset	3,878	2,631
Derivative Liability, Fair Value, Gross Liability	3,031	2,716
Total Return Swap [Member]
Credit Derivative Instruments - TRS Contracts [Line Items]
Derivative, Notional Amount	2,543	2,009
Derivative Asset, Fair Value, Gross Asset	38	97
Derivative Liability, Fair Value, Gross Liability	34	94
Collateral Already Posted, Aggregate Fair Value	$ 635	$ 601

[Line Items] for Credit Derivative Instruments - TRS Contracts [Table]

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Fair value, before 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 elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before 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 elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Nominal or face amount used to calculate payment on derivative.

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