Solar Energy Systems, Net - Components of Solar Energy Systems, Net (Parenthetical) (Detail) - Solar Energy Systems [Member] - USD ($) $ in Millions |
Sep. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Finance Leased Assets [Line Items] | ||
| Gross finance leased assets | $ 36 | $ 36 |
| Accumulated depreciation and amortization on finance leased assets | $ 7 | $ 6 |