CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	[1]	Mar. 31, 2017
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net income		$ 208		$ 351
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[2]
Comprehensive income		$ 208		$ 351

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

[2] Net of $1 million in taxes for the three months ended March 31, 2017.