Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 155	$ 214	$ 212
Other comprehensive income (loss)- Change in compensation retirement benefits liability and amortization, net of taxes of $1 million in 2020 and immaterial amounts in 2019 and 2018	(1)	(1)	1
Comprehensive income	$ 154	$ 213	$ 213