Leases Schedule of Lease Assets and Liabilities (Details) $ in Millions	Mar. 31, 2019 USD ($)
Schedule of Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	$ 703	[1]
Current Operating Lease Liabilities	213	[2]
Noncurrent Operating Lease Liabilities	494	[3]
Total Operating Lease Liabilities	707
Finance Lease, Right-of-Use Asset, Gross	152
Finance Lease, Right-Of-Use Asset, Accumulated Depreciation	(38)
Finance Lease, Liability	126
Property, Plant and Equipment [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Right-of-Use Asset	114
Short-term Debt [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Liability, Current	43
Long-term Debt [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Liability, Noncurrent	$ 83

[1] Included in other assets in the interim Condensed Consolidated Balance Sheet.

[2] Included in accrued and other current liabilities in the interim Condensed Consolidated Balance Sheet.

[3] Included in other noncurrent obligations in the interim Condensed Consolidated Balance Sheet.