Postretirement Benefits (Postretirement Benefit Adjustments Recognized In Other Comprehensive (Loss) Income) (Details) - Other Postretirement Benefits Plan [Member] $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial (loss) gain	$ 2
Amortization of actuarial loss	(2)
Current year prior service cost	0
Amortization of prior service credit	3
Currency impact	1
Total recognized in other comprehensive income	4
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial (loss) gain	(34)
Amortization of actuarial loss	(9)
Current year prior service cost	0
Amortization of prior service credit	2
Currency impact	0
Total recognized in other comprehensive income	$ (41)