Retirement Plans (Schedule of Changes In Defined Benefit Plan Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	$ 880	$ 981
Service cost			$ 5
Interest cost	19	18	25
Actuarial gain	(215)	(18)
Plan curtailments		22
Plan settlements		(73)
Benefits paid	(55)	(50)
Benefit obligation at end of year	629	880	981
Change in plan assets:
Fair value of plan assets at beginning of year	671	745
Actual return on plan assets	(172)	(11)
Employer contributions	14	60
Plan settlements		(73)
Benefits paid	(55)	(50)
Fair value of plan assets at end of year	458	671	745
Funded status at end of year	(171)	(209)
Amounts recognized in balance sheet:
Other long-term assets		6
Other current liabilities	(14)	(14)
Other long-term liabilities	(157)	(201)
Net amount	(171)	(209)
Amounts recognized in accumulated other comprehensive earnings:
Net actuarial loss (gain)	189	206
Total	189	206
Postretirement Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	12	13
Actuarial gain	(4)	(1)
Plan amendments		1
Participant contributions	1	2
Benefits paid	(2)	(3)
Benefit obligation at end of year	7	12	$ 13
Change in plan assets:
Employer contributions	1	1
Participant contributions	1	2
Benefits paid	(2)	(3)
Funded status at end of year	(7)	(12)
Amounts recognized in balance sheet:
Other current liabilities	(1)	(2)
Other long-term liabilities	(6)	(9)
Net amount	(7)	(11)
Amounts recognized in accumulated other comprehensive earnings:
Net actuarial loss (gain)	(15)	(12)
Prior service cost	1	1
Total	$ (14)	$ (11)