Employee Benefit Plans (Accumulated Other Comprehensive Loss Pretax Amounts Not Yet Reflected in Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated net actuarial losses/(gains)	$ 682	$ 748
Accumulated prior service credit	0	0
Total	682	748
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated net actuarial losses/(gains)	(15)	(16)
Accumulated prior service credit	(20)	(10)
Total	$ (35)	$ (26)