Discontinued Operations and Held-For-Sale Businesses (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset Impairment Charges					$ 1,066	$ 277	$ 355
Net loss from disposal and impairments of discontinued operations					(3)	(1)	(225)
Other Asset Impairment Charges	$ 849	$ 69	$ 116		864	185	208
Income (Loss) from Continuing Operations Attributable to Parent					(43)	(302)	(985)
Disposal Group, Including Discontinued Operation, Assets, Noncurrent		0			1,251	0
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent					$ 3	$ 1	$ 218
Borsod [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation Deferred Gain on Disposal		26
Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses)		$ 20
Eletropaulo Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Equity Method Investment Retained after Disposal, Ownership Interest after Disposal				17.00%
Proceeds from divestiture of business			340
Net loss from disposal and impairments of discontinued operations			(199)
Impairment Expense Pre Tax Total			$ 243