Basis of Presentation (Reclassification) (Details) - USD ($) $ in Millions	3 Months Ended								6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of Reclassification From Prior Period [Line Items]
Net income	$ 459	$ 326	$ 308	$ 337	$ 540	$ 311	$ 214	$ 357	$ 645	$ 971	$ 1,430	$ 1,422	$ 1,431
Investments	119				135						119	135
Purchases of shares from noncontrolling interests											(77)	(39)	4
Receivables, net				97					128	228	(86)	(83)	(25)
Other assets and liabilities				72					65	94	50	118	(43)
Increase (decrease) in restructuring reserve												31	83
Accounts Receivable
Summary of Reclassification From Prior Period [Line Items]
Reclassification adjustment											170	170	170
Non-current Deferred Tax Asset
Summary of Reclassification From Prior Period [Line Items]
Reclassification adjustment											(66)	(66)	(66)
Retained Earnings
Summary of Reclassification From Prior Period [Line Items]
Reclassification adjustment											(104)	(104)	$ (104)
Scenario, Previously Reported
Summary of Reclassification From Prior Period [Line Items]
Net income	509	314	280	327	590	303	188	341	607	921	1,430	1,422
Receivables, net				110					175	289
Other assets and liabilities				69					56	83
Restatement Adjustment
Summary of Reclassification From Prior Period [Line Items]
Net income	$ (50)	$ 12	$ 28	10	$ (50)	$ 8	$ 26	$ 16			$ 0	$ 0
Adjustments for New Accounting Pronouncement | Restatement Adjustment
Summary of Reclassification From Prior Period [Line Items]
Net income				10					38	50
Receivables, net				(13)					(47)	(61)
Other assets and liabilities				$ 3					$ 9	$ 11