Leases - Supplemental Balance Sheet Information (Details) $ in Millions	Dec. 31, 2019 USD ($)
Operating leases
Operating Lease Right-of-Use Assets	$ 2,013
Current portion of operating lease liabilities	365
Long-Term Operating Lease Liabilities	1,780
Total operating lease liabilities	2,145
Finance Leases
Property, Plant and Equipment, net	166
Current portion of long-term debt	13
Long-Term Debt	150
Total finance lease liabilities	$ 163
Weighted Average Remaining Lease Term (Years)
Operating leases	8 years 1 month 6 days
Finance leases	11 years 6 months
Weighted Average Discount Rate - Operating leases (percent)	3.02%
Weighted Average Discount Rate - Finance leases (percent)	3.05%