CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Comprehensive income:
Net income	$ 695	$ 727	$ 660
Net pension and retiree medical gain (loss) arising during the period, net of tax	0	(1)	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	1	0	0
Derivative instruments:
Reclassification of loss to net income, net of tax	1	1	2
Total other comprehensive income	2	0	2
Total comprehensive income	$ 697	$ 727	$ 662