NONCONSOLIDATED AFFILIATES (Schedule of the Company's Direct or Indirect Ownership Interest in Principal Nonconsolidated Affiliates) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($) jointventures	Dec. 31, 2019 USD ($) jointventures	Dec. 31, 2018 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Interest, Number of Affiliates \| jointventures	35	37
Investment in nonconsolidated affiliates	$ 1,327	$ 1,404	$ 3,320
Other noncurrent obligations	(169)	(80)
Net investment in principal nonconsolidated affiliates	1,158	1,324
Equity in earnings (losses) of nonconsolidated affiliates	(18)	(94)	555
Principal Nonconsolidated Affiliates
Schedule of Equity Method Investments [Line Items]
Investment in nonconsolidated affiliates	922	963
Other noncurrent obligations	(169)	(80)
Net investment in principal nonconsolidated affiliates	753	883
Equity in earnings (losses) of nonconsolidated affiliates	$ (16)	$ 21	$ 561
EQUATE Petrochemical Company K.S.C.
Schedule of Equity Method Investments [Line Items]
Ownership percentage	42.50%	42.50%	42.50%
Other noncurrent obligations	$ (147)	$ (80)
The Kuwait Olefins Company K.S.C.
Schedule of Equity Method Investments [Line Items]
Ownership percentage	42.50%	42.50%	42.50%
The Kuwait Styrene Company KSC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	42.50%	42.50%	42.50%
Map Ta Phut Olefins Company
Schedule of Equity Method Investments [Line Items]
Ownership percentage	32.77%	32.77%	32.77%
Equity Method Investment, Ownership Percentage, Direct	20.27%
Equity Method Investment, Ownership Percentage, Indirect	12.50%
Sadara Chemical Company
Schedule of Equity Method Investments [Line Items]
Ownership percentage	35.00%	35.00%	35.00%
Other noncurrent obligations	$ (22)	$ 0
Siam Polyethylene Company Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%	50.00%
Siam Polystyrene Company Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%	50.00%
Siam Styrene Monomer Company Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%	50.00%
Siam Synthetic Latex Company Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%	50.00%

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