Accumulated Other Comprehensive Loss - Changes in AOCL, After Tax and Minority Interest (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 4,837	$ 5,466
Ending balance	4,798	5,424
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,613)	(1,663)
Other comprehensive income (loss) before reclassifications	(6)	34
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	(1,619)	(1,629)
Unrealized Gains (Losses) from Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1	1
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	1	1
Unrecognized Net Actuarial Losses and Prior Service Costs
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,224)	(2,215)
Other comprehensive income (loss) before reclassifications	4	(2)
Amounts reclassified from accumulated other comprehensive loss	17	21
Ending balance	(2,203)	(2,196)
Deferred Derivative Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1	2
Other comprehensive income (loss) before reclassifications	(0)	(2)
Amounts reclassified from accumulated other comprehensive loss	1	0
Ending balance	2	0
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(3,835)	(3,875)
Other comprehensive income (loss) before reclassifications	(2)	30
Amounts reclassified from accumulated other comprehensive loss	18	21
Ending balance	$ (3,819)	$ (3,824)