Accumulated Other Comprehensive Income - Amounts Reclassified (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses	$ (749)	$ (779)
Interest expense	(263)	(253)
Income taxes	60	(93)
NET INCOME	74	320
Reclassifications from AOCI \| Gains & Losses on Cash Flow Hedges
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
NET INCOME	0	1
Reclassifications from AOCI \| Gains & Losses on Cash Flow Hedges \| Long-term debt
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	0	1
Reclassifications from AOCI \| Net prior service costs
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses	(23)	(7)
Income taxes	5	1
NET INCOME	$ (18)	$ (6)

[Line Items] for Reclassification out of Accumulated Other Comprehensive Income [Table]

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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