Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income (loss)	$ 104	$ 347	$ (239)
Foreign currency translation adjustment	48	(25)	(16)
Net change in derivative financial instruments	(106)	(45)	(67)
Net change in available-for-sale securities	5	(6)	0
Net change in unrealized costs associated with certain retirement plans	(6)	(11)	27
Total other comprehensive income (loss)	(59)	(87)	(56)
Total comprehensive income (loss)	$ 45	$ 260	$ (295)