Accumulated Other Comprehensive Loss - Changes in AOCL, After Tax and Minority Interest (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 5,184	$ 3,259
Ending balance	5,322	3,286
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,402)	(1,284)
Other comprehensive income (loss) before reclassifications	11	(32)
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	(1,391)	(1,316)
Unrecognized Net Actuarial Losses and Prior Service Costs
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,565)	(2,856)
Other comprehensive income (loss) before reclassifications	16	9
Amounts reclassified from accumulated other comprehensive loss	24	27
Ending balance	(2,525)	(2,820)
Deferred Derivative Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	4	5
Other comprehensive income (loss) before reclassifications	(2)	1
Amounts reclassified from accumulated other comprehensive loss	(1)	(2)
Ending balance	1	4
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(3,963)	(4,135)
Other comprehensive income (loss) before reclassifications	25	(22)
Amounts reclassified from accumulated other comprehensive loss	23	25
Ending balance	$ (3,915)	$ (4,132)