Solar Energy Systems, Net - Components of Solar Energy Systems, Net (Detail) - Solar Energy Systems [Member] - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Solar energy systems in service	$ 6,744	$ 6,682
Initial direct costs related to customer solar energy system lease acquisition costs	103	102
Solar energy systems, gross	6,847	6,784
Less: accumulated depreciation and amortization	(897)	(723)
Solar energy systems, gross, less accumulated depreciation and amortization	5,950	6,061
Solar energy systems under construction	25	18
Solar energy systems pending interconnection	50	59
Solar energy systems, net	$ 6,025	$ 6,138