Restructuring - Schedule of Restructuring Reserve (Details) - 2017 Plan - USD ($) $ in Millions	3 Months Ended	9 Months Ended	33 Months Ended
Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2019
Restructuring Plan
Balance as of December 31, 2018		$ 201
Expensed	$ 125	260	$ 1,263
Cash payments		(322)
Foreign currency translation		(1)
Balance as of September 30, 2019		$ 138	$ 138

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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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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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

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