CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ (593)	$ 49	$ (3,020)	$ 781
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[1]	1	1	1	5
Comprehensive income (loss)		$ (592)	$ 50	$ (3,019)	$ 786

[1] Tax benefits for the three months ended September 30, 2020 were immaterial. Net of less than $1 million in tax benefits for the nine months ended September 30, 2020 and the three months ended September 30, 2019 and $2 million in tax benefits for the nine months ended September 30, 2019. In 2019, primarily related to settlement of pension assets.