STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Other Comprehensive Income [Abstract]
Net income (loss)	$ 1,486	$ (773)	$ 791
Other comprehensive income (loss):
Adjustment to pension and other postretirement plans	21	(5)	12
Net deferred loss from cash flow hedges	0	0	(2)
Reclassification of deferred loss from cash flow hedges realized in net income	2	0	1
Reclassification of net deferred losses from cash flow hedges	0	15	0
Other comprehensive loss from unconsolidated affiliates, net of tax	3	(2)	(1)
Total	26	8	10
Comprehensive income (loss)	1,512	(765)	801
Income allocated to preferred shareholders	95	176	117
Comprehensive income (loss) available to common shareholders	$ 1,417	$ (941)	$ 684