CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	[1]	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net income (loss)		$ 537	$ 1,046		$ (2,643)
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[2]	10	2		13
Net loss incurred in period	[3]	(2)	(13)		(7)
Total change in value of pension and postretirement liabilities		8	(11)		6
Change in currency translation adjustment			6		3
Comprehensive income (loss)		$ 545	$ 1,041		$ (2,634)

[1] In 2018 and 2017, deferred tax activity incurred in other comprehensive income was offset by a valuation allowance.

[2] Net of $8 million in taxes for the year ended December 31, 2016.

[3] Net of ($4) million in taxes for the year ended December 31, 2016.