Accumulated Other Comprehensive Loss - Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reclassifications out of accumulated other comprehensive income loss by component
Interest expense	$ (337)	$ (384)	$ (689)	$ (773)
Income tax expense	(109)	(168)	(311)	(325)
Other (expense) income, net	(122)	52	(52)	86
Total before tax	453	674	1,254	1,306
Net income	344	506	943	981
Decrease (Increase) in Net Income | Interest rate swaps
Reclassifications out of accumulated other comprehensive income loss by component
Interest expense	0	21	22	41
Income tax expense	0	(5)	(5)	(10)
Net income	0	16	17	31
Decrease (Increase) in Net Income | Net actuarial loss
Reclassifications out of accumulated other comprehensive income loss by component
Other (expense) income, net	30	50	67	100
Decrease (Increase) in Net Income | Prior service cost
Reclassifications out of accumulated other comprehensive income loss by component
Other (expense) income, net	0	1	(1)	3
Decrease (Increase) in Net Income | Defined benefit plan
Reclassifications out of accumulated other comprehensive income loss by component
Income tax expense	(8)	(12)	(17)	(25)
Total before tax	30	51	66	103
Net income	$ 22	$ 39	$ 49	$ 78