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Related Party and Affiliate Transactions (Details) $ in Millions, lb in Billions		12 Months Ended
	Jun. 17, 2015 lb	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 12, 2019	Oct. 28, 2019
Related Party Transaction [Line Items]
Investments in joint ventures			$ 225
Related party receivable		$ 9	12
Dividends received from equity method investments		12	11	$ 5
Affiliates [Member]
Related Party Transaction [Line Items]
Plant capacity (in lbs) \| lb	2.2
Incurred and paid lease payments		3	3	3
LACC, LLC [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)					34.80%	12.00%
Cash contributions		4	45
RS Cogen LLC [Member]
Related Party Transaction [Line Items]
Cash contributions		14
Pipeline Fees For Transport Of Natural Gas Liquid Feedstocks [Member] \| Cypress Interstate Pipeline L.L.C [Member] \| Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Purchases from related parties		13	14	14
Accounts payable due to affiliate		$ 1	1
Cypress Interstate Pipeline L.L.C [Member] \| Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Investments in joint ventures		$ 7	8
YNCORIS GmbH & Co. KG [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		20.00%
Investments in joint ventures		$ 64	57
YNCORIS GmbH & Co. KG [Member] \| Electricity And Technical Services [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Purchases from related parties		149	155	145
Accounts payable due to affiliate		$ 41	36
RS Cogen LLC [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Investments in joint ventures		$ 26	9
Purchases from related parties		$ 29	26	25
Vinyl Solutions, LLC [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Sales to related parties		$ 4	5	13
Related party receivable		1	2
American Air Liquide Holdings [Member] \| American Air Liquide Holdings, Inc. [Member]
Related Party Transaction [Line Items]
Sales to related parties		7	7	7
Related party receivable		1	0
Purchases and lease expense to related parties		34	32	$ 31
Accounts payable due to related parties		$ 3	$ 2