Derivative Instruments and Hedging Activities (Pre-Tax Gains (Losses) On Derivatives Designated As Hedging Instruments) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Nonoperating Income (Expense)									$ 37	$ 147	$ 350
Interest expense									330	293	308
Revenues	$ 16,070	$ 14,827	$ 14,943	$ 14,988	$ 16,501	$ 15,832	$ 15,629	$ 14,384	60,828	62,346	67,702
Cost of products sold									57,322	58,727	63,736
Sales [Member]
Derivative [Line Items]
Commodity contracts ineffective amount recognized in earnings										(5)	6
Total amount recognized in earnings										(40)	47
Designated As Hedging Instrument [Member]
Derivative [Line Items]
Total amount recognized in earnings									(47)	(136)	41
Designated As Hedging Instrument [Member] | Nonoperating Income (Expense) [Member]
Derivative [Line Items]
FX Contracts effective amount recognized in earnings									(2)	(18)	29
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness											1
Total amount recognized in earnings									(2)	(18)	30
Designated As Hedging Instrument [Member] | Interest Expense [Member]
Derivative [Line Items]
Interest contracts effective amount recognized in earnings									1	(2)	1
Total amount recognized in earnings									1	(2)	1
Designated As Hedging Instrument [Member] | Cost Of Products Sold [Member]
Derivative [Line Items]
Commodity Contracts effective amount recognized in earnings									(45)	(82)	(25)
Commodity contracts ineffective amount recognized in earnings										6	(12)
Total amount recognized in earnings									(45)	(76)	(37)
Designated As Hedging Instrument [Member] | Sales [Member]
Derivative [Line Items]
Commodity Contracts effective amount recognized in earnings									(1)	$ (35)	$ 41
Total amount recognized in earnings									$ (1)