Retirement Plans (Schedule Of Changes In Defined Benefit Plan Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	$ 1,308	$ 1,377
Service cost	15	33	$ 30
Interest cost	42	52	55
Actuarial loss (gain)	63	(68)
Plan amendments	2
Plan curtailments	(31)
Plan settlements	(94)
Foreign exchange rate changes	1	(6)
Benefits paid	(57)	(80)
Benefit obligation at end of year	1,249	1,308	1,377
Change in plan assets:
Fair value of plan assets at beginning of year	1,059	1,149
Actual return on plan assets	61	(16)
Employer contributions	16	11
Plan settlements	(94)
Benefits paid	(57)	(80)
Foreign exchange rate changes		(5)
Fair value of plan assets at end of year	985	1,059	1,149
Funded status at end of year	(264)	(249)
Amounts recognized in balance sheet:
Other long-term assets	3	2
Other current liabilities	(13)	(12)
Other long-term liabilities	(254)	(239)
Net amount	(264)	(249)
Amounts recognized in accumulated other comprehensive earnings:
Net actuarial loss (gain)	285	302
Prior service cost (credit)	8	14
Total	293	316
Postretirement Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	23	24
Service cost		1	1
Interest cost	1	1	1
Actuarial loss (gain)	(1)	(2)
Plan amendments		1
Participant contributions		2
Benefits paid	(2)	(4)
Benefit obligation at end of year	21	23	$ 24
Change in plan assets:
Employer contributions	2	2
Participant contributions		2
Benefits paid	(2)	(4)
Funded status at end of year	(21)	(23)
Amounts recognized in balance sheet:
Other current liabilities	(3)	(3)
Other long-term liabilities	(18)	(20)
Net amount	(21)	(23)
Amounts recognized in accumulated other comprehensive earnings:
Net actuarial loss (gain)	(11)	(11)
Prior service cost (credit)	(5)	(6)
Total	$ (16)	$ (17)