CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 80	$ (1,547)
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[1]	0	0
Comprehensive income (loss)		$ 80	$ (1,547)

[1] The amortization of prior service costs and net loss along with corresponding tax benefits for the three months ended March 31, 2021 and March 31, 2020 were immaterial.