Accumulated Other Comprehensive Income (AOCI) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	$ (2,278)	$ (2,604)
Other comprehensive income (loss) before reclassifications	417	664
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax	(64)	166
Amounts reclassified from AOCI	(166)	(231)
Other comprehensive income (loss), tax, portion attributable to parent	(30)	(116)
Other Comprehensive Income (Loss), Net of Tax	157	483
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(2,121)	(2,121)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(2,186)	(2,424)
Other comprehensive income (loss) before reclassifications	99	163
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax	(64)	166
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), tax, portion attributable to parent	8	(48)
Other Comprehensive Income (Loss), Net of Tax	43	281
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(2,143)	(2,143)
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	261	185
Other comprehensive income (loss) before reclassifications	320	496
Amounts reclassified from AOCI	(238)	(313)
Other comprehensive income (loss), tax, portion attributable to parent	(15)	(40)
Other Comprehensive Income (Loss), Net of Tax	67	143
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	328	328
Pension Liability Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(352)	(365)
Other comprehensive income (loss) before reclassifications	(1)	7
Amounts reclassified from AOCI	72	82
Other comprehensive income (loss), tax, portion attributable to parent	(22)	(27)
Other Comprehensive Income (Loss), Net of Tax	49	62
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(303)	(303)
Unrealized Gain (Loss) On Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(1)	0
Other comprehensive income (loss) before reclassifications	(1)	(2)
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), tax, portion attributable to parent	(1)	(1)
Other Comprehensive Income (Loss), Net of Tax	(2)	(3)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	$ (3)	$ (3)