Financial Instruments Derivatives Not Designated as Hedging, Fair Value Table (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Derivative contracts, at fair value (Note 6)	$ 1,224	$ 36
Investment Segment
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Collateral posted on certain derivative positions	903	0
Investment Segment \| Not designated as hedging instrument
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Asset derivatives, Gross	291	651
Liability derivatives, Gross	1,324	170
Derivative, Fair Value, Amount Offset Against Collateral, Net	(109)	(134)
Investment Segment \| Not designated as hedging instrument \| Other assets
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Derivative contracts, at fair value(1)	182	517
Investment Segment \| Not designated as hedging instrument \| Accrued expenses and other liabilities
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Derivative contracts, at fair value (Note 6)	1,215	36
Investment Segment \| Not designated as hedging instrument \| Equity Contract [Member]
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Asset derivatives, Gross	291	568
Liability derivatives, Gross	1,058	170
Investment Segment \| Not designated as hedging instrument \| Credit Risk Contract [Member]
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Asset derivatives, Gross	0	76
Liability derivatives, Gross	266	0
Investment Segment \| Not designated as hedging instrument \| Commodity Contract [Member]
Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]
Asset derivatives, Gross	0	7
Liability derivatives, Gross	$ 0	$ 0

Derivatives Not Designated as Hedging Instruments, Fair Value [Line Items]

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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, 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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The net amount as of the balance sheet date of the fair value of derivative assets and derivative liabilities that in accordance with the entity's accounting policy were offset against collateral under a master netting arrangement.

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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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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.

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