Revenue Contract Balances (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Accounts and notes receivable - trade	[1]	$ 5,619	$ 4,130
Contract assets - current	[2]	36	48
Deferred revenue recognized during the period		460
Accrued and Other Current Liabilities [Member]
Disaggregation of Revenue [Line Items]
Deferred Revenue	[3]	2,033	1,927
Other noncurrent obligations
Disaggregation of Revenue [Line Items]
Deferred Revenue	[4]	$ 28	$ 30

[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.