Accumulated Other Comprehensive Income (AOCI) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	$ (2,705)	$ (2,405)
Other comprehensive income (loss) before reclassifications	(10)	(388)
Amounts reclassified from AOCI	(66)	40
Other comprehensive income (loss), tax, portion attributable to parent	32	4
Other Comprehensive Income (Loss), Net of Tax	(44)	(344)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(2,749)	(2,749)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(2,445)	(2,152)
Other comprehensive income (loss) before reclassifications	(155)	(434)
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), tax, portion attributable to parent	51	37
Other Comprehensive Income (Loss), Net of Tax	(104)	(397)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(2,549)	(2,549)
Deferred Gain (Loss) On Hedging Activities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(14)	(12)
Other comprehensive income (loss) before reclassifications	178	76
Amounts reclassified from AOCI	(66)	35
Other comprehensive income (loss), tax, portion attributable to parent	(22)	(23)
Other Comprehensive Income (Loss), Net of Tax	90	88
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	76	76
Pension Liability Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(275)	(268)
Other comprehensive income (loss) before reclassifications	(5)	(5)
Amounts reclassified from AOCI	0	5
Other comprehensive income (loss), tax, portion attributable to parent	3	(9)
Other Comprehensive Income (Loss), Net of Tax	(2)	(9)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(277)	(277)
Unrealized Gain (Loss) On Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	29	27
Other comprehensive income (loss) before reclassifications	(28)	(25)
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), tax, portion attributable to parent	0	(1)
Other Comprehensive Income (Loss), Net of Tax	(28)	(26)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	$ 1	$ 1