Other Financial Information - Schedule of Interest Cost Components (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Financial Information [Abstract]
Amount charged to expense	$ 121	$ 122	$ 104
Amount capitalized	13	14	17
Interest costs, total	$ 134	$ 136	$ 121