Restructuring - Restructuring Expenses Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring	$ (2)	$ 53	$ (3)	$ 59

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Period Type:	duration