Discontinued Operations and Held-For-Sale Businesses (Narrative) (Details) - USD ($) $ in Millions		1 Months Ended		3 Months Ended							6 Months Ended	12 Months Ended
	Oct. 31, 2016	Dec. 31, 2017	Jun. 30, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Provided by (Used in) Operating Activities, Discontinued Operations													$ 164		$ 529
Cash Provided by (Used in) Investing Activities, Discontinued Operations													(288)		(368)
Disposal Group, Including Discontinued Operation, Revenue													3,320		4,036
Disposal Group, Including Discontinued Operation, Costs of Goods Sold													(3,151)		(3,954)
Asset Impairment Charges												$ 355	537		1,098
Net loss from disposal and impairments of discontinued operations												(225)	611		1,119
Other Asset Impairment Charges				$ 42	$ 74	$ 92	$ 277	$ 90	$ 168			208	537		1,096
Income (Loss) from Continuing Operations Attributable to Parent												(985)	507		20
Impairment Expense Pre Tax Total													(611)		(1,385)
Disposal Group, Including Discontinued Operation, Other Expense													(166)	[1]	(160)
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax													3		(78)
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax													(608)		(1,463)
Income (loss) on discontinued operations, before tax, attributable to Noncontrolling interest													(25)		(142)
Income (loss) from discontinued operations, before income tax, attributable to parent													(633)		(1,605)
Discontinued Operation, Tax Effect of Discontinued Operation													(21)		495
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent												$ 218	(654)		(1,110)
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%
Deconsolidation, Gain (Loss), Amount							$ (611)
Net loss from disposal and impairments of discontinued operations						(199)
Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses)													(455)
Disposal Group, Including Discontinued Operation, Pension Gains (Losses)													(243)
Impairment Expense Pre Tax Total						$ 243
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax													$ (633)		(192)
Sul Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss from disposal and impairments of discontinued operations	$ (737)		$ (382)												(1,100)
Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses)										$ 1,000
Reduction in Stockholders equity due to sale of business															92
Assets carrying amount			1,600
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal			266
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax															$ (1,400)
Eletropaulo Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of business											$ 340
Sul Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal			135
Proceeds from Divestiture of Businesses, Net of Cash Divested	$ 484
Discontinued Operations, Held-for-sale [Member] | Sul Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other Asset Impairment Charges			$ 783

[1] Includes a loss contingency recognized by our equity method investment in discontinued operations.