Debt and Finance Leases - Annual Payments Based on the Maturities of Debt and Capital Leases (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
2020	$ 88
2021	6
2022	5
2023	4
2024	604
Thereafter	5,335
Subtotal long-term debt and finance leases (including current maturities)	6,042	$ 6,692
Revolving Credit Facility \| Revolver Facility \| Line of Credit
Debt Instrument [Line Items]
2020	$ 83

Amount of short-term and long-term debt and lease obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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