Accumulated Other Comprehensive Loss - Changes in AOCL, After Tax and Minority Interest (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 4,837	$ 5,466
Ending balance	4,855	5,273
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	(55)	31
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	(1,668)	(1,632)
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	10	11
Amounts reclassified from accumulated other comprehensive loss	37	69
Ending balance	(2,177)	(2,135)
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	(4)
Amounts reclassified from accumulated other comprehensive loss	1	0
Ending balance	2	(2)
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	(45)	38
Amounts reclassified from accumulated other comprehensive loss	38	69
Ending balance	$ (3,842)	$ (3,768)