Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income (loss)	$ 1,671	$ 104	$ 347
Foreign currency translation adjustment	(21)	48	(25)
Net change in derivative financial instruments	110	(106)	(45)
Net change in available-for-sale securities	0	5	(6)
Net change in defined benefit pensions and other items	2	(6)	(11)
Total other comprehensive income (loss)	91	(59)	(87)
Total comprehensive income (loss)	$ 1,761	$ 45	$ 260