Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net income (loss)	$ 154	$ 555	$ 578	$ 853
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	0	(45)	7	(36)
Net change in derivative financial instruments	(9)	158	40	78
Net change in defined benefit pensions and other items	0	0	(1)	0
Total other comprehensive income (loss)	(9)	112	45	42
Total comprehensive income (loss)	$ 144	$ 668	$ 623	$ 895