Shareholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Balance		$ 15,770	$ 17,960		$ 18,863
Other comprehensive income	[1]	(256)	757	[2]	(175)	[3]
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[4]	93	42	[5]	62	[5]
Equity method affiliates	[1]	(5)	35	[6]	248	[6],[7]
Net current-period other comprehensive income	[1]	(168)	834		135
Balance		13,886	15,770		17,960
Other Comprehensive Income, Tax		64	97		52
Other Comprehensive Income (Loss), Equity Method Investments, Tax			20
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	[1]	(529)	(1,275)		(1,171)
Other comprehensive income	[1]	(180)	711	[2]	(89)	[3]
Equity method affiliates	[1]	(5)	35	[6]	(15)	[6],[7]
Net current-period other comprehensive income	[1]	(185)	746		(104)
Balance	[1]	(714)	(529)		(1,275)
Other Comprehensive Income, Tax		34	4		36
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	[1]	(317)	(347)		(588)
Other comprehensive income	[1]	(84)	13	[2]	(63)	[3]
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[4]	103	17	[5]	40	[5]
Equity method affiliates	[1],[6],[7]				264
Net current-period other comprehensive income	[1]	19	30		241
Balance	[1]	(298)	(317)		(347)
Other Comprehensive Income, Tax		(3)	88		12
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	[1]	(3)	(17)		(14)
Other comprehensive income	[1]	(1)			(2)	[3]
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[5]		14
Equity method affiliates	[1],[6],[7]				(1)
Net current-period other comprehensive income	[1]	(1)	14		(3)
Balance	[1]	(4)	(3)		(17)
Other Comprehensive Income, Tax					1
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	[1]	7	(37)		(38)
Other comprehensive income	[1]	9	33	[2]	(21)	[3]
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(10)	11	[5]	22	[5]
Net current-period other comprehensive income	[1]	(1)	44		1
Balance	[1]	6	7		(37)
Other Comprehensive Income, Tax		33	5		3
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Balance	[1]	(842)	(1,676)		(1,811)
Balance	[1]	$ (1,010)	$ (842)		$ (1,676)

[1] All amounts are after tax. Amounts in parentheses indicate debits to accumulated other comprehensive income.

[2] Amounts are net of total tax benefit of $64 million, including $34 million related to the foreign currency translation adjustments, $33 million related to the retirement plans component and $(3) million related to the hedges component.

[3] Amounts are net of total tax expense of $97 million, including $88 million related to the foreign currency translation adjustments, $5 million related to the hedges component and $4 million related to the retirement plans component.

[4] Amounts in parentheses indicate debits to the statement of income.

[5] Tax effects of reclassifications are disclosed separately in this Note 15.

[6] Tax effects related to equity method affiliates are not significant in the reported periods except for the tax expense of $20 million related to the pension component in 2016.

[7] Most of the changes in equity method affiliate accumulated other comprehensive income components in 2016 relate to disposal transactions with amounts reclassified to the income statement.