Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Supplemental Income Statement Elements [Abstract]
Depreciation	$ 41	$ 46	$ 124	$ 137
Capital expenditures	$ 32	$ 34	$ 85	$ 99