Fair Value of Financial Instruments - Schedule of Estimated Fair Values and Carrying Values (Detail) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Carrying Value | $ 10,402 | $ 8,411 |
| Convertible Senior Notes [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Carrying Value | 3,686 | 3,661 |
| Fair Value | 6,067 | 4,347 |
| 5.30% Senior Notes due in 2025 ("2025 Notes") [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Carrying Value | 1,782 | 1,779 |
| Fair Value | 1,748 | 1,575 |
| Solar asset-backed notes [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Carrying Value | 1,155 | 1,183 |
| Fair Value | 1,211 | 1,207 |
| Solar Loan-backed Notes [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Carrying Value | 175 | 203 |
| Fair Value | $ 189 | $ 212 |