Consolidated Statements of Comprehensive Income - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income	$ 244,000,000	$ 155,000,000	$ 214,000,000
Other comprehensive income (loss)- Change in compensation retirement benefits liability and amortization, net of taxes of an immaterial amount in 2021, $1 million in 2020, and an immaterial amount in 2019	1,000,000	(1,000,000)	(1,000,000)
Comprehensive income	$ 245,000,000	154,000,000	$ 213,000,000
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Abstract]
Taxes on Other Comprehensive Income		$ 1,000,000