Business Segment and Geographic Information (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) Division Countries Customers		Mar. 31, 2017 USD ($)	Dec. 31, 2017 Countries Customers
Concentration Risk [Line Items]
Number of business segments | Division	2
Impairments and other charges	$ 265	[1]	$ 0
Gain (Loss) on Extinguishment of Debt			104
Early Repayment of Senior Debt			1,400
Maximum Percentage Gross Trade Receivables From One Geographic Segment	10.00%			10.00%
Maximum Percentage Gross Trade Receivables From One Customer	10.00%			10.00%
Number of Countries Exceed Receivables Threshold | Countries	1			1
Number of Customers Exceed Receivables Threshold | Customers	0			0
Foreign Currency Exchange Rate, Remeasurement	50,000			10
Maximum number of days receivables outstanding in Venezuela	90 days
Impairments and other charges, net of tax	$ 312		$ 0
VENEZUELA
Concentration Risk [Line Items]
Allowance for Doubtful Accounts Receivable, Write-offs	119
Write-off of promissory note in Venezuela	32
Inventory Write-down	48
Fixed asset write-offs in Venezuela	53
Other asset and liability write-offs in Venezuela	13
Accrued taxes portion of Venezuela investment write-down	$ 47
Geographic Concentration Risk [Member] | UNITED STATES | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	47.00%		42.00%

[1] Represents a pre-tax charge of $265 million related to a write-down of all of our remaining investment in Venezuela, consisting of receivables, fixed assets, inventory and other assets and liabilities in the three months ended March 31, 2018.