Equity - Summary of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	$ (1,402)	$ (1,505)
Cash flow hedges — unrealized net gain (loss)	(62)	(67)
Postretirement and postemployment benefits:
Net experience loss	(13)	(14)
Prior service cost	11	11
Total accumulated other comprehensive income (loss)	$ (1,466)	$ (1,575)	[1]

[1] Condensed from audited financial statements.