Restructuring Plans - Table (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Plans
Accrued balance at beginning of the period	$ 79	$ 70	$ 119
Restructuring charges	36	66	28
Payments and other adjustments	(45)	(57)	(77)
Accrued balance at end of the period	$ 70	$ 79	$ 70

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration