Pension and Other Postretirement Benefits - Schedule of Pension Plan Benefit Obligations (Details) - Pension benefits - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 1,592	$ 1,599	$ 2,296
Accumulated benefit obligation	1,591	1,598
The aggregate projected benefit obligation and fair value of plan assets for pension plans with projected benefit obligations in excess of plan assets were as follows:
Projected benefit obligation	1,459	1,482
Fair value of plan assets	780	833
The aggregate accumulated benefit obligation and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets were as follows:
Accumulated benefit obligation	1,459	1,481
Fair value of plan assets	$ 780	$ 833