Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax	$ 33	$ (9)	$ (22)
Net Unrealized gains (losses) on available-for-sale securities, tax	(1)	(1)	1
Net unrealized holding losses arising during period,tax	0	(1)	4
Cash flow hedges reclassified to earnings, tax	(2)	(2)	(3)
Pension and post retirement benefits, tax	(4)	21	(1)
Pension and post retirement benefits reclassified to earnings, tax	$ (3)	$ (2)	$ (2)