Revenue Contract Balances (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Deferred Revenue, Revenue Recognized		$ 1,973
Accounts and notes receivable - trade	[1]	4,130	$ 87	$ 3,976
Contract assets - current	[2]	48	40	0
Accrued and Other Current Liabilities [Member]
Disaggregation of Revenue [Line Items]
Deferred Revenue	[3]	1,927	2	2,014
Other Noncurrent Obligations [Member]
Disaggregation of Revenue [Line Items]
Deferred Revenue	[4]	$ 30	$ 0	$ 48

[1] Included in accounts and notes receivable - net in the Consolidated Balance Sheets.

[2] Included in other current assets in the Consolidated Balance Sheets.

[3] Included in accrued and other current liabilities in the Consolidated Balance Sheets.

[4] Included in other noncurrent obligations in the Consolidated Balance Sheets.