Employee Benefit Plans (Changes In Defined Benefit Obligation And Fair Value Of Defined Benefit Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning	$ 2,448
Fair value of plan assets, ending	1,736	$ 2,448
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation, beginning	3,109	2,992
Service cost	66	78	$ 82
Interest cost	93	106	113
Actuarial loss (gain)	278	(129)
Employee contributions	2	2
Curtailments	(1)	0
Settlements	(528)	(6)
Defined Benefit Plan, Benefit Obligation, Business Combination	0	3
Benefits paid	(99)	(86)
Plan Amendments	2	(180)
Actual expenses	0	(2)
Foreign currency effects	(43)	73
Benefit obligation, ending	2,323	3,109	2,992
Fair value of plan assets, beginning	2,448	2,131
Actual return on plan assets	(122)	340
Employer contributions	66	29
Employee contributions	2	2
Settlements	(528)	(6)
Benefits Paid	(99)	(86)
Actual Expenses	0	(2)
Foreign currency effects	(31)	40
Fair value of plan assets, ending	1,736	2,448	2,131
Funded status	(587)	(661)
Prepaid benefit cost	53	55
Accrued benefit liability - current	(17)	(17)
Accrued benefit liability - long-term	(623)	(699)
Net amount recognized in the balance sheet	(587)	(661)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation, beginning	154	171
Service cost	2	2	3
Interest cost	5	6	8
Actuarial loss (gain)	4	(4)
Curtailments	0	0
Settlements	0
Benefits paid	(13)	(11)
Plan Amendments	0	(10)
Foreign currency effects	0	0
Benefit obligation, ending	144	154	$ 171
Fair value of plan assets, beginning	0
Employer contributions	13	11
Benefits Paid	(13)	(11)
Fair value of plan assets, ending	0	0
Funded status	(144)	(154)
Accrued benefit liability - current	(13)	(12)
Accrued benefit liability - long-term	(131)	(142)
Net amount recognized in the balance sheet	$ (144)	$ (154)