Leases Schedule of Lease Assets and Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Schedule of Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	[1]	$ 543
Operating Lease, Liability, Current	[2]	149
Operating Lease, Liability, Noncurrent	[3]	407
Operating Lease, Liability		556
Finance Lease, Right-of-Use Asset, Gross		15
Finance Lease, Right-Of-Use Asset, Accumulated Depreciation		(7)
Finance Lease, Liability, Current		4	$ 25	$ 6
Finance Lease, Liability		10
Property, Plant and Equipment [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Right-of-Use Asset		8
Short-term Debt [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Liability, Current		4
Long-term Debt [Member]
Schedule of Lease Assets and Liabilities [Line Items]
Finance Lease, Liability, Noncurrent		$ 6

[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.