CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 828	$ (3,575)	$ 785	$ (13,719)
Other comprehensive income (loss) items:
Pension and postretirement gains (losses)	[1]	(45)	28	4	(63)
Gains (losses) on derivatives		2	(1)	3	2
Other		(1)	2	(1)	(1)
Other comprehensive income (loss), net of tax		(44)	29	6	(62)
Comprehensive income (loss) attributable to preferred and common stockholders		$ 784	$ (3,546)	$ 791	$ (13,781)

[1] Net of tax benefit (expense) of zero and $(8) million for the three months ended September 30, 2021 and 2020, respectively, and $(13) million and $18 million for the nine months ended September 30, 2021 and 2020, respectively.