Employee Benefit Plans - Components of Net Periodic Benefit Costs (Details) - Pension Benefits Cost - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Components of expense/ (income) related to net benefit expense:
Service Cost Included in Labor and Fringe	$ 6	$ 6
Interest Cost	26	28
Expected Return on Plan Assets	(42)	(41)
Amortization of Net Loss	5	7
Total Included in Other Income - Net	(11)	(6)
Net Periodic Benefit Credit	$ (5)	$ 0