General - Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Change in Accounting Estimate [Line Items]
Overstatement of accounts receivables	$ 1,165			$ 1,165		$ 1,383
Overstatement (reduction) of revenues	1,363		$ 1,402	2,749	$ 2,987
Reduction in net income	(171)		$ (565)	(619)	(1,063)
Accounts receivables, net of allowance for uncollectible accounts	1,165			1,165		$ 1,383
Venezuela
Change in Accounting Estimate [Line Items]
Overstatement of accounts receivables	153			153
Accounts receivables, net of allowance for uncollectible accounts	153			153
Other Non-Current Assets | Venezuela
Change in Accounting Estimate [Line Items]
Overstatement of accounts receivables	150			150
Accounts receivables, net of allowance for uncollectible accounts	150			150
Revenue recognition adjustment
Change in Accounting Estimate [Line Items]
Overstatement (reduction) of revenues					(23)
Accounting change adjustment	31	$ 8			$ 23
Interest Income (Expense), Net	4
Accounts Receivable, Net, Current	$ 27			$ 27