Pension, Postretirement And Other Employee Benefit Plans - Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs (Details) - Level 3 - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets at beginning of year	$ 333	$ 435
Actual income (loss) on plan assets:
Sold during the year	(50)	34
Held at year end	55	(39)
Purchases, sales, issuances and settlements (net)	(16)	(97)
Fair value of plan assets at end of year	$ 322	$ 333