Consolidated Statement of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flow hedging activities:
Other Comprehensive Income, Net Unrealized Gain (Loss) from Derivatives, Tax	$ 1	$ 2	$ (1)
Other Comprehensive Income Loss, Reclassification into Earnings of Net Derivative Instruments (Gain) Loss, Tax	(1)	(1)	1
Foreign currency translation activities:
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	0	0	(37)
Other Comprehensive Income (Loss), Foreign Currency Translation Reclassification into Earnings upon Sale, Tax	0	0	(36)
Pension and other postretirement benefits:
Other Comprehensive Income, Amortization Of Defined Benefit Plan Net Prior Service Cost (Credit) In Net Periodic Benefit Cost (Credit), Tax	0	2	2
Other Comprehensive Income (Loss), Defined Benefit Plan, Net Actuarial Gain (Loss) Arising During Period, Tax	3	(15)	8
Other Comprehensive Income Loss, Reclassification Pension And Other Postretirement Benefit Plans Net Gain Loss Included In Net Periodic Benefit Cost (Credit), Tax	$ (11)	$ (37)	$ (12)