Fair Value of Financial Instruments - Schedule of Estimated Fair Values and Carrying Values (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	$ 8,462	$ 10,402
Convertible Senior Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,971	3,729
Fair Value	24,596	6,110
2025 Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,785	1,782
Fair Value	1,877	1,748
Solar asset-backed notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,115	1,155
Fair Value	1,137	1,211
Solar Loan-backed Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	146	175
Fair Value	$ 152	$ 189