Annual report pursuant to Section 13 and 15(d)

Other Comprehensive Income (Component of Other Comprehensive Income) (Details)

v3.8.0.1
Other Comprehensive Income (Component of Other Comprehensive Income) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Other Comprehensive Income (Loss), Net of Tax [Abstract]      
Foreign currency translation adjustments before tax $ 156 $ (96) $ (119)
Tax (expense) benefit from foreign currency translation gain (loss) (21) 13 17
Foreign currency translation adjustments, net-of-tax $ 135 $ (83) $ (102)