Employee Benefit Plans - Components of Net Periodic Benefit Costs (Details) - Pension Benefits Cost - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Components of expense/ (income) related to net benefit expense:
Service Cost Included in Labor and Fringe	$ 6	$ 8	$ 12	$ 16
Interest Cost	28	16	56	32
Expected Return on Plan Assets	(41)	(47)	(82)	(94)
Amortization of Net Loss	7	13	14	25
Total Included in Other Income - Net	(6)	(18)	(12)	(37)
Net Periodic Benefit Credit	$ 0	$ (10)	$ 0	$ (21)