Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Other comprehensive income (loss)	$ 156	$ (52)
Net Effect of Exchange Rate Fluctuations
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(1,290)	(1,229)
Change before reclassifications	130	(81)
Other comprehensive income (loss)	130	(81)
Balance at end of the period	(1,160)	(1,310)
Change in Certain Derivative Instruments
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(21)	(60)
Change before reclassifications	18	63
Amounts reclassified from accumulated other comprehensive income (loss)	(15)	(50)
Other comprehensive income (loss)	3	13
Balance at end of the period	(18)	(47)
Employee Benefit Plans
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(661)	(983)
Change before reclassifications	(2)	3
Amounts reclassified from accumulated other comprehensive income (loss)	14	19
Translation effect	6	(2)
Other comprehensive income (loss)	18	20
Balance at end of the period	(643)	(963)
Accumulated Other Comprehensive Loss.
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(1,972)	(2,272)
Change before reclassifications	146	(15)
Amounts reclassified from accumulated other comprehensive income (loss)	(1)	(31)
Translation effect	6	(2)
Other comprehensive income (loss)	151	(48)
Balance at end of the period	$ (1,821)	$ (2,320)