COMMITMENTS AND CONTINGENT LIABILITIES (Guarantees) (Table and Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Guarantor Obligations [Line Items]
Long-term Debt	$ 19,529	$ 19,594
Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Final expiration	2023	2023
Guarantor obligations, maximum future payments	$ 4,514	$ 4,523
Guarantor obligations, recorded liability	$ 15	25
Sadara Chemical Company [Member]
Guarantor Obligations [Line Items]
Equity Method Investment, Ownership Percentage	35.00%
Sadara Chemical Company [Member] \| Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum future payments	$ 4,200
Sadara Chemical Company [Member] \| Total Project Financing [Member]
Guarantor Obligations [Line Items]
Project Financing, Maximum Borrowing Capacity	12,500
Long-term Debt	$ 11,700	$ 11,700

Final expiration year of guarantees of the reporting entity.

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Face (par) amount of debt instrument at time of issuance.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

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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.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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