Leases - Classification of Finance Leases (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finance Leases
Property, plant and equipment	$ 13,659	$ 12,864
Less: Accumulated depreciation and amortization	9,687	9,337
Property, plant and equipment, net	3,972	3,527
Current portion of long-term debt	5	10
Long-term debt, net	3,424	2,316
Total finance lease liabilities	7
Finance leases
Finance Leases
Property, plant and equipment	20	20
Less: Accumulated depreciation and amortization	7	5
Property, plant and equipment, net	13	15
Current portion of long-term debt	0	1
Long-term debt, net	7	7
Total finance lease liabilities	$ 7	$ 8

Finance Lease [Abstract]

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- Definition

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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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount of long-term debt and lease obligation, classified as current.

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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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