CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	[1]	Jun. 30, 2019	Jun. 30, 2018	[1]
Statement of Comprehensive Income [Abstract]
Net income		$ 138	$ 51		$ 732	$ 259
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[2]	4	0		4	0
Comprehensive income		$ 142	$ 51		$ 736	$ 259

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

[2] Primarily related to settlement of pension assets in the second quarter of 2019. Net of $1 million in taxes for the three and six months ended June 30, 2019.