CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (497)	$ (206)	$ (888)	$ (377)
Net income attributable to noncontrolling interest		2	1	2
Net loss attributable to controlling interest	(497)	(208)	(889)	(379)
Components of net periodic benefit costs before reclassifications			(9)	7
Components of net periodic benefit costs reclassified to net loss	2	1	4	1
Other comprehensive income (loss) before income taxes	2	1	(5)	8
Other comprehensive income (loss)	2	1	(5)	8
Other comprehensive income (loss) attributable to controlling interest	2	1	(5)	8
Total comprehensive loss	(495)	(205)	(893)	(369)
Total comprehensive income attributable to noncontrolling interest		2	1	2
Total comprehensive loss attributable to controlling interest	$ (495)	$ (207)	$ (894)	$ (371)