Shareholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance	$ 12,133	$ 13,521	$ 12,997	$ 13,886
Net current-period other comprehensive income (loss)	298	(257)	37	(377)
Balance	12,857	13,134	12,857	13,134
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(1,064)	(786)	(857)	(714)
Other comprehensive income (loss)	274	(235)	75	(293)
Equity method affiliates	9	(3)	1	(17)
Net current-period other comprehensive income (loss)	283	(238)	76	(310)
Balance	(781)	(1,024)	(781)	(1,024)
Other Comprehensive Income, Tax	21	(16)	10	(39)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	9	8	51	6
Other comprehensive income (loss)	11	(21)	(40)	(16)
Amounts reclassified from accumulated other comprehensive income (loss)		(1)	9	(4)
Net current-period other comprehensive income (loss)	11	(22)	(31)	(20)
Balance	20	$ (14)	20	$ (14)
Other Comprehensive Income, Tax	$ 5		$ 11