Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 66	$ 52	$ 83	$ 104
Other comprehensive (loss) income, net of income taxes:
Employee benefit plans	(1)	(1)	(2)	(1)
Interest rate derivatives	14	4	2	11
Other comprehensive income, net of income taxes	13	3	0	10
Comprehensive income	$ 79	$ 55	$ 83	$ 114