Summary of Significant Accounting Standards and Policies - PP&E and accumulated depreciation (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Property, plant and equipment and depreciation
PP&E impairment	$ 0
Property, plant and equipment, at cost	5,362	$ 5,113
Accumulated depreciation	(3,056)	(2,915)
Property, plant and equipment, net	2,306	2,198
Land
Property, plant and equipment and depreciation
Property, plant and equipment, at cost	202	199
Building
Property, plant and equipment and depreciation
Property, plant and equipment, at cost	748	715
Machinery and Equipment
Property, plant and equipment and depreciation
Property, plant and equipment, at cost	$ 4,412	$ 4,199

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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