Employee Benefits - Schedule of Net Periodic Benefit Cost / Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other changes in plan assets and benefit obligations recognized in other comprehensive income, net of tax
Total recognized	$ 13	$ 44	$ (23)
Non-Cash settlement charge of unamortized actuarial loss, before tax	23	13	3
Retirement Plans
Components of net periodic cost for retirement plans and post-retirement plans
Service cost	2	3	4
Interest cost	74	48	40
Expected return on assets	(101)	(87)	(104)
Actuarial loss (gain)	6	15	21
Prior service credit	0	0	0
Net periodic benefit cost	(19)	(21)	(39)
Settlement charge	23	13	3
Total net periodic benefit cost	4	(8)	(36)
Other changes in plan assets and benefit obligations recognized in other comprehensive income, net of tax
Net actuarial loss (gain)	33	67	(6)
Recognized actuarial (gain) loss	(5)	(12)	(15)
Prior service cost	0	0	0
Settlement charge	(18)	(10)	(2)
Total recognized	10	45	(23)
Postretirement Plans
Components of net periodic cost for retirement plans and post-retirement plans
Service cost	0	0	0
Interest cost	1	1	1
Expected return on assets	0	0	0
Actuarial loss (gain)	(2)	(2)	(2)
Prior service credit	(2)	(2)	(1)
Net periodic benefit cost	(3)	(3)	(2)
Settlement charge	0	0	0
Total net periodic benefit cost	(3)	(3)	(2)
Other changes in plan assets and benefit obligations recognized in other comprehensive income, net of tax
Net actuarial loss (gain)	1	(3)	(1)
Recognized actuarial (gain) loss	1	1	1
Prior service cost	1	1	(1)
Settlement charge	0	0	0
Total recognized	$ 3	$ (1)	$ (1)