Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income	$ 214	$ 212	$ 187
Other comprehensive (loss) income - Change in compensation retirement benefits liability and amortization, net of taxes of an immaterial amount in 2019, 2018, and 2017	(1)	1	(1)
Comprehensive income	$ 213	$ 213	$ 186