DERIVATIVE FINANCIAL INSTRUMENTS - Offsetting Assets (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets	$ 2,384	$ 856
Gross amounts offset in the condensed consolidated balance sheets	1,302	404
Net amounts of assets presented in the condensed consolidated balance sheets	1,082	452
Gross amounts not offset in the condensed consolidated balance sheets, Financial instruments	(115)	(65)
Gross amounts not offset in the condensed consolidated balance sheets, cash collateral received	(62)	(29)
Net amount	$ 905	$ 358

Fair value of liability associated with 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, and obligation to return cash collateral under master netting arrangements.

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

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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, after effects of master netting arrangements, of 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 offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

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