General - Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Change in Accounting Estimate [Line Items]
Overstatement of accounts receivables	$ 1,236			$ 1,236		$ 1,383
Overstatement (reduction) of revenues	1,460		$ 1,356	4,209	$ 4,343
Reduction in net income	(256)		$ (1,780)	(875)	$ (2,843)
Accounts receivables, net of allowance for uncollectible accounts	1,236			1,236		1,383
Other Non-Current Assets | Venezuela
Change in Accounting Estimate [Line Items]
Overstatement of accounts receivables	158			158
Accounts receivables, net of allowance for uncollectible accounts	$ 158			$ 158
Revenue recognition adjustment
Change in Accounting Estimate [Line Items]
Overstatement (reduction) of revenues						$ (23)
Accounting change adjustment		$ 31
Interest Income (Expense), Net		4
Accounts Receivable, Net, Current		$ 27